Sounds similar to Roblox silently loses connection without notice or rejoin option .
If you have Roblox’s voice chat, you can check if it’s the same issue because when you disconnect you can still hear others after disconnecting.
You can also check if it’s the same issue by checking for the [DFLog::RakNetMissingPingPong] Decryption failed in your logs, if it is there please upload your logs for the engineers looking into the issue.