I hope you had a merry christmas.
Some time ago I reported that after upgrading from Kubuntu 19.10 to 20.04 the telnet DX cluster freezes after a few minutes. Even after upgrading to Kubuntu 20.10 the behavior has not changed.
The simultaneously running RBN monitor does not show this behavior and continues to work even after the Telnet DX cluster freezes.
Both windows use the same telnet server "telnet.reversebeacon.net".
In the meantime, any idea what this could be? Maybe also a problem with the database.