Thanks a lot for the information! Someone else tried installing 5 alpha and then reverting to 4.18, so I don't think that was responsible for the improvement, which means removing ultrapeer connections seems to be the key. That suggests a subset of ultrapeers are buggy or misbehaving. I'll add some extra code to the condi tool to log the vendor and version number of each connection - maybe we can spot a pattern. Thanks again!