Orientation switch in Android app (Brave) not working

The Brave Browser doesn’t switch from vertical to horizontal orientation when I turn the phone. My question: is this a known issue? Maybe an issue in general with Android apps (on XA2 phone)?

(not sure if this question should go to bug category?)
(as a side remark, I would have preferred the Firefox browser but the Aptoid store failed to install)

To answer myself: there is a known [] Screen Rotation doesn't work in Android Apps issue which also refer a https://talk.maemo.org/showthread.php?t=101015 thread with more details. Sorry, didn’t find this before…

The suggestion (vertical/dynamic display orientation, start/stop AlienDalvik) from the thread didn’t work initially but suddenly later after I run the sailfish browser in vertical position and start/stopped Dalvik some more, Brave rotated to vertical. Strange. It’s also strange that it worked here (XA2 with 3.4) when the problem resurfaced for the maemo thread author with 3.4 (on XA2Ultra).

(I mark this as solution (explanation) and - if possible - will close here)