Thank you for your answer and link, your post was one I missed during my search (I did read some of the answers in search though)
I’m sad and relieved to see I’m not alone with this issue, hope they’ll be able to fix it soon.
I’ll come back to tell if the problem returns while “download automatically” is still turned on.
(did you check MMC and MNC parameters automatically configured with those your provider asks for ? See here: https://github.com/sailfishos/mobile-broadband-provider-info/blob/master/mobile-broadband-provider-info/serviceproviders.xml
The update might have changed one it shouldn’t )
Thank you !