Did you test all the servers?
I sometimes get the problem with the official ones (eu 1,2,3,5 and 6) showing me a ping of 50-100ms, but feeling way more laggy. Also, lagspikes there, that all the players on the server fell (atleast those in my ts). If they are in this state, I usualy switch to the pecores servers (eu4s) and get my normal 15-20ms.