I don’t know what problems you found, but the biggest bugs I encountered in past years seem to be fixed now, at least on recent clients. (Element X is recent, and I’ve seen praise for FluffyChat.)
Matrix for text and Mumble for voice works well for me.
I see luck with “combos”
XMPP + Mumble is a common one. The room is on XMPP, some users are in a mumble server with info in the topic.
Matrix is buggy and doesn’t scale imo, it isn’t a sustainable alternative. Stoat looks like a great option and there are lots of open instances.
I don’t know what problems you found, but the biggest bugs I encountered in past years seem to be fixed now, at least on recent clients. (Element X is recent, and I’ve seen praise for FluffyChat.)
Matrix for text and Mumble for voice works well for me.