Chatty unresponsive after joining matrix room

I have a matrix account configured in chatty on the Librem 5 and it has worked until today.

It stopped working today when I joined another matrix room. The room I joined was the "Mobian" room (#mobian:matrix.org) I joined the Mobian room not on the Librem 5 but on another device (a laptop) using another matrix client (nheko), and after that chatty became unresponsive on the Librem 5.

Not sure what goes wrong, but a theory is that the Mobian room has lots of recent activity and that chatty gets overwhelmed when trying to fetch data from there.

Now when I try to start chatty it sometimes does not appear at all, and sometimes it appears but does not respond to touches.

journalctl shows error messages like this:

jan 11 16:54:20 pureos chatty[1725]: gst_element_message_full_with_details: assertion 'GST_IS_ELEMENT (element)' failed

and like this:

jan 11 16:54:20 pureos sm.puri.Chatty-daemon.desktop[1725]: Oops, secure memory pool already initialized

but those are nothing new, I have seen those earlier also, before today, before this problem started.

Running chatty --debug from the command-line shows some complaints about purple, for example:

[...]
(17:18:28) plugins: /usr/lib/purple-2/liboscar.so is not usable because the 'purple_init_plugin' symbol could not be found.  Does the plugin call the PURPLE_INIT_PLUGIN() macro?
[...]
(17:18:28) plugins: /usr/lib/purple-2/libjabber.so is not usable because the 'purple_init_plugin' symbol could not be found.  Does the plugin call the PURPLE_INIT_PLUGIN() macro?
[...]
(17:18:28) plugins: /usr/lib/purple-2/tcl.so is not loadable: libtcl8.6.so: cannot open shared object file: No such file or directory
[...]
(17:18:28) pounce: Error reading pounces: Failed to open file “/home/purism/.purple/pounces.xml”: No such file or directory
(17:18:30) mediamanager: Registered Audio/Source device Built-in Audio Headset Microphone + Stereo Microphones + Handset Microphone
(17:18:30) mediamanager: Registered Audio/Source device Modem Stereo
(17:18:30) mediamanager: Registered Audio/Sink device Built-in Audio Headphones + Speaker + Handset
(17:18:30) mediamanager: Registered Audio/Sink device Modem Stereo
(17:18:37) util: Writing file prefs.xml to directory /home/purism/.purple
(17:18:37) util: Writing file /home/purism/.purple/prefs.xml
(17:18:37) util: Writing file status.xml to directory /home/purism/.purple
(17:18:37) util: Writing file /home/purism/.purple/status.xml
(17:23:31) prefs: /purple/savedstatus/isidleaway changed, scheduling save.
(17:23:36) util: Writing file prefs.xml to directory /home/purism/.purple
(17:23:36) util: Writing file /home/purism/.purple/prefs.xml

Not sure if any of that is related. Do the above messages indicate that I am missing some purple-related package that chatty needs?

The message "util: Writing file /home/purism/.purple/prefs.xml" seen above is the last line of output, then chatty seems to just hang. I can see the newly added Mobian room in the top of the list of conversations shown in chatty, but chatty is not responding to touches.

I tried killing chatty and starting it again, then the same thing happens, it hangs in the same way again.

How to find out why chatty is hanging like this, what is it doing?