Voice call bug: call drops then reconnects as soon as you send a message

https://streamable.com/m879n2  << screen recording of what happens

Basically what happens is the other person will randomly drop out of the call without doing anything. Then when I leave the call, it permanently ends. As soon as I send a text message, the call restarts with the other person already in it, even though they didn't do anything. It also doesn't ring or alert me that a call has started. After this, I am able to join the call once again, until the other person drops and everything loops over and over. I'd like to note that whenever I am in the call, I can talk to the other person normally, it's just an issue with the call randomly disconnecting and then magically starting back up without any prompt.

This happens almost every week, seemingly at random. There are no internet issues on either side, and the connection signals show that it is full signal and good connection from both parties.

Anyone else experiencing this or know what is causing this?

EDIT: If I don't rejoin the magic call, it will end permanently after 5 minutes like it normally does if there's only one person in it. No matter how long has passed since the call has ended, even if it's 2 hours after, if I send a text message it will magically start again.