Short update, just for completeness, as meanwhile I could track this further down, and is probably limited to the (non-current) OS version: On a Lineage 14.1 device, I can reproduce the effect as follows: when I open one account, and then leave back with the arrow on top left, then and only then I get thrown back to the AppIntro. With using the system-“back” button instead, this does not happen.
Reproduced so far on two Lineage phones, does not happen on two stock android phones (also when based on same Android base version), thus I’d conclude it’s just a Lineage weirdness. 😉
