I have:
Some disappearing messages are still visible after their expiration time has passed. They only disappear after force-closing Signal and reopening it.
I've observed this happening twice but no clear way on how to to reproduce
Actual result: The messages are sometimes still present
Expected result: The messages should have disappeared
I opened the message when it was received at 8:04pm, the message I had sent a few hours earlier was gone (as expected). The received message was still present when I opened the conversation again at 11:21pm (over 3 hours later). Disappearing time was 30 minutes and the timer had expired (the hourglass is empty, the message details say "Disappears 1 second").

Device: BlackBerry PRIV
Android version: 6.0.1
Signal version: 3.20.4
https://gist.github.com/anonymous/0e3155fbb68a7ca2039be761bf1bfc7f
I've noticed the exact same thing. I've set Signal to use a password, if that could be why.
https://gist.github.com/anonymous/8fc9bea189c74f458bec8d5e37dd66c8
I can confirm this behaviour on Android as well, a very small number of messages never disappears. I do not use a password for Signal. Currently on stock Android 7.0 with October 5:th security patches.
Can also confirm on android 7.1.1 Signal version 3.21.3 october patches installed
Samsung Galaxy Note 7 Edge, running Android 6.0.1 on Verizon. Android version of Signal is 3.25.4
https://gist.github.com/anonymous/d876044f91deb9b560dc5d9035f7afe4 (this log does not go back far in time when the messages actually were meant to disappear as user expected it to disappear "3 hours ago" from the time of sharing the log)
This has been open for quite some time, so I just wanted to throw my hat into the 'me too' ring. Android 7.1.1 on a Nexus 6p. I am running Signal 4.0.0.
@Enekk @cwaldren Debug logs are really what's needed here. I know the devs don't like the "me too" posts. You can get the same effect of the "me too" by using the emoticon reaction for ones you have but don't have extra data or logs.
Here are the debug logs captured at the moment where this was happening to me. https://gist.github.com/anonymous/ca571f2a3e6bd763956b4530be274053 I believe the message was at around 20 minutes old even though it should have been culled after 5.
Edit: This doesn't happen consistently, so I'll try to grab a log when it does.
Running into this too intermittently. Almost seems like the timer starts over. The corresponding messages ARE deleted from the desktop client, however, at the correct time.
I also confirm this on android 7.1.2 (patch level 5. Dez 17) with Signal version 4.13.7.
Edit: In my case, it seems that no messages disappear.
GitHub Issue Cleanup:
See #7598 for more information.
Most helpful comment
@Enekk @cwaldren Debug logs are really what's needed here. I know the devs don't like the "me too" posts. You can get the same effect of the "me too" by using the emoticon reaction for ones you have but don't have extra data or logs.