OMEMO: the 42 days issue
This post is a bug report and a feature request in one.
So in a nutshell: At the moment in encrypted groups where you only read and do not write a word, after 42 days your own fingerprints are deleted by the other users. This feature should be selectable. There are groups in which only one or two people write and the rest of the group only reads along, and the users are then prevented from reading along.
It is already clear to me that everyone in the group must turn off the feature.
This was probably intended to remove fingerprints that were not used after 42 days. But at the moment users who are online every day are prevented from reading because the rest of the users delete the fingerprint of the user after 42 days. But even that should be allowed to decide the user. Automatic deletion is always a hairy matter.
For example, if you are at a party and there are some pretty people who feel like girls and do not want to dance, but just watch others dance, then you can not exclude people just because they do not want to dance.