As seen from my message, I have also an android phone and the admin responded to me, that they are both equally managed. He will try to find any extra settings for this SFOS phone on MS admin portal, nothing found so far.
I have started debug mode and then started a singled mail referesh task. This is the verbose log I got (anonymized) - it is not helpful to me:
čet. apr. 28 23:06:47 2022 Info: , 0: Sync folders: account: 76 , folderIds: ("243") , requestId: 4
čet. apr. 28 23:06:47 2022 Info: , 0: Start request: 4 for account 76 at 165118000XXXX
čet. apr. 28 23:06:47 2022 Debug: , 0: AS Command URL: "https://outlook.office365.com:443/Microsoft-Server-ActiveSync?Cmd=FolderSync&User=robert@com.com&DeviceId=h31133XXXX&DeviceType=SailfishOS"
čet. apr. 28 23:06:47 2022 Debug: , 0: -------------------------------------
čet. apr. 28 23:06:47 2022 Debug: , 0: Sending folder sync command via POST:
čet. apr. 28 23:06:47 2022 Debug: FolderSyncCommand::start, 84: WBXML tree:
[EAS]START_DOCUMENT
[EAS]<FolderSync>
[EAS] <SyncKey>1</SyncKey>
[EAS]</FolderSync>
[EAS]END_DOCUMENT
čet. apr. 28 23:06:47 2022 Debug: , 0: -------------------------------------
čet. apr. 28 23:06:47 2022 Info: , 0: reporting sync started 4 for account: 76
čet. apr. 28 23:06:48 2022 Debug: , 0: progress 25 / -1
čet. apr. 28 23:06:48 2022 Debug: , 0: progress 25 / 25
čet. apr. 28 23:06:48 2022 Debug: , 0: =========================
čet. apr. 28 23:06:48 2022 Debug: , 0: Received folder sync command reply:
čet. apr. 28 23:06:48 2022 Debug: , 0: Network error: QNetworkReply::NetworkError(NoError)
čet. apr. 28 23:06:48 2022 Debug: , 0: Headers: (QPair("Cache-Control","private"), QPair("Content-Type","application/vnd.ms-sync.wbxml"), QPair("Content-Encoding","gzip"), QPair("Vary","Accept-Encoding"), QPair("Server","Microsoft-IIS/10.0"), QPair("request-id","9ae51bf1-xxxx"), QPair("Strict-Transport-Security","max-age=31536000; includeSubDomains; preload"), QPair("Alt-Svc","h3=\":443\",h3-29=\":443\""), QPair("X-CalculatedFETarget","AM0XXXX.internal.outlook.com"), QPair("X-CalculatedBETarget","AS4XXXX.eurprd05.PROD.OUTLOOK.COM"), QPair("X-BackEndHttpStatus","200, 200"), QPair("X-RUM-Validated","1"), QPair("MS-Server-ActiveSync","15.20"), QPair("X-MS-BackOffDuration","L/-469"), QPair("X-AspNet-Version","4.0.30319"), QPair("X-DiagInfo","AS4XXXX"), QPair("X-BEServer","AS4XXXX"), QPair("X-Proxy-RoutingCorrectness","1"), QPair("X-Proxy-BackendServerStatus","200"), QPair("X-FEProxyInfo","AM6XXXX.EURP194.PROD.OUTLOOK.COM"), QPair("X-FEEFZInfo","DHR"), QPair("X-FirstHopCafeEFZ","DHR"), QPair("X-Powered-By","ASP.NET"), QPair("X-FEServer","AM0XXXX, AM6XXXX"), QPair("Date","Thu, 28 Apr 2022 21:06:47 GMT"))
čet. apr. 28 23:06:48 2022 Debug: , 0: Length: 25
čet. apr. 28 23:06:48 2022 Debug: FolderSyncCommand::handleFinished, 147: WBXML tree:
[EAS]START_DOCUMENT
[EAS]<FolderSync>
[EAS] <Status>1</Status>
[EAS] <SyncKey>1</SyncKey>
[EAS] <Changes>
[EAS] <Count>0</Count>
[EAS] </Changes>
[EAS]</FolderSync>
[EAS]END_DOCUMENT
čet. apr. 28 23:06:48 2022 Debug: , 0: =========================
čet. apr. 28 23:06:48 2022 Info: , 0: Successfully parsed folder sync command response!
čet. apr. 28 23:06:48 2022 Info: , 0: Status: 1
čet. apr. 28 23:06:48 2022 Info: , 0: SyncKey: "1"
čet. apr. 28 23:06:48 2022 Info: , 0: added: ()
čet. apr. 28 23:06:48 2022 Info: , 0: updated: ()
čet. apr. 28 23:06:48 2022 Info: , 0: deleted: ()
čet. apr. 28 23:06:48 2022 Info: , 0: FolderSync command finished: true
čet. apr. 28 23:06:48 2022 Info: , 0: adding local synchronised folder for sync: "Inbox" "9"
čet. apr. 28 23:06:48 2022 Info: , 0: Marking collection for sync due to needing sync: "Inbox" "9"
čet. apr. 28 23:06:48 2022 Info: , 0: Server ID: "9" , syncKey: "209281XXXX"
čet. apr. 28 23:06:48 2022 Info: , 0: Have collection: "9" = "243" with syncKey: "209281XXXX" - requires normal sync.
čet. apr. 28 23:06:48 2022 Info: , 0: initialSync size 0 , sync size 1
čet. apr. 28 23:06:48 2022 Info: , 0: Performing continue sync, collections: 1
čet. apr. 28 23:06:48 2022 Debug: , 0: AS Command URL: "https://outlook.office365.com:443/Microsoft-Server-ActiveSync?Cmd=Sync&User=robert@com.com&DeviceId=h31133XXXX&DeviceType=SailfishOS"
čet. apr. 28 23:06:48 2022 Debug: , 0: ------------------------------
čet. apr. 28 23:06:48 2022 Debug: , 0: Sending sync command via POST:
čet. apr. 28 23:06:48 2022 Debug: SyncCommand::start, 108: WBXML tree:
[EAS]START_DOCUMENT
[EAS]<Sync>
[EAS] <Collections>
[EAS] <Collection>
[EAS] <SyncKey>209281XXXX</SyncKey>
[EAS] <CollectionId>9</CollectionId>
[EAS] <DeletesAsMoves>0</DeletesAsMoves>
[EAS] <GetChanges>1</GetChanges>
[EAS] <Options>
[EAS] <FilterType>2</FilterType>
[EAS] <MIMETruncation>0</MIMETruncation>
[EAS] <MIMESupport>1</MIMESupport>
[EAS] <BodyPreference>
[EAS] <Type>1</Type>
[EAS] <Preview>255</Preview>
[EAS] </BodyPreference>
[EAS] <BodyPreference>
[EAS] <Type>2</Type>
[EAS] <Preview>255</Preview>
[EAS] </BodyPreference>
[EAS] </Options>
[EAS] </Collection>
[EAS] </Collections>
[EAS]</Sync>
[EAS]END_DOCUMENT
čet. apr. 28 23:06:48 2022 Debug: , 0: ------------------------------
čet. apr. 28 23:06:48 2022 Debug: , 0: progress 0 / 0
čet. apr. 28 23:06:48 2022 Debug: , 0: =========================
čet. apr. 28 23:06:48 2022 Debug: , 0: Received sync command reply:
čet. apr. 28 23:06:48 2022 Debug: , 0: Network error: QNetworkReply::NetworkError(NoError)
čet. apr. 28 23:06:48 2022 Debug: , 0: Headers: (QPair("Cache-Control","private"), QPair("Content-Type","application/vnd.ms-sync.wbxml"), QPair("Server","Microsoft-IIS/10.0"), QPair("request-id","5866fd3f-xxxx"), QPair("Strict-Transport-Security","max-age=31536000; includeSubDomains; preload"), QPair("Alt-Svc","h3=\":443\",h3-29=\":443\""), QPair("X-CalculatedFETarget","AM0XXXX.internal.outlook.com"), QPair("X-CalculatedBETarget","AS4XXXX.eurprd05.PROD.OUTLOOK.COM"), QPair("X-BackEndHttpStatus","200, 200"), QPair("X-RUM-Validated","1"), QPair("MS-Server-ActiveSync","15.20"), QPair("X-MS-BackOffDuration","L/-469"), QPair("X-AspNet-Version","4.0.30319"), QPair("X-DiagInfo","AS4XXXX"), QPair("X-BEServer","AS4XXXX"), QPair("X-Proxy-RoutingCorrectness","1"), QPair("X-Proxy-BackendServerStatus","200"), QPair("X-FEProxyInfo","AM6XXXX.EURP194.PROD.OUTLOOK.COM"), QPair("X-FEEFZInfo","DHR"), QPair("X-FirstHopCafeEFZ","DHR"), QPair("X-Powered-By","ASP.NET"), QPair("X-FEServer","AM0XXXX, AM6XXXX"), QPair("Date","Thu, 28 Apr 2022 21:06:48 GMT"), QPair("Content-Length","0"))
čet. apr. 28 23:06:48 2022 Debug: , 0: Length: 0
čet. apr. 28 23:06:48 2022 Debug: SyncCommand::handleFinished, 250: QVariant(QString, "WBXML tree: <empty>\n")
čet. apr. 28 23:06:48 2022 Debug: , 0: =========================
čet. apr. 28 23:06:48 2022 Info: , 0: Nothing to parse
čet. apr. 28 23:06:48 2022 Info: , 0: Successfully parsed sync command response!
čet. apr. 28 23:06:48 2022 Info: , 0: status: Eas::SyncStatusUndefined
čet. apr. 28 23:06:48 2022 Info: , 0: limit: 0
čet. apr. 28 23:06:48 2022 Info: , 0: Sync command finished: true
čet. apr. 28 23:06:48 2022 Info: , 0: Successfully finished sync request!
čet. apr. 28 23:06:48 2022 Info: , 0: Update last synchronized QDateTime(2022-04-28 23:06:48.569 CEST Qt::TimeSpec(LocalTime)) for service "Exchange Email"
čet. apr. 28 23:06:48 2022 Info: , 0: onRequestCompleted: 4 for account 76
čet. apr. 28 23:06:48 2022 Info: , 0: reporting sync completed 4 for account: 76 with status 0
čet. apr. 28 23:06:48 2022 Info: , 0: reporting request 4 finished with status 0
čet. apr. 28 23:06:48 2022 Info: , 0: updating connection account config
čet. apr. 28 23:06:48 2022 Info: , 0: updating email account config
čet. apr. 28 23:06:48 2022 Info: , 0: account 76 updated
čet. apr. 28 23:12:03 2022 Info: , 0: database is released