When I got the connection everywhere was 300ms+, I provided them traceroutes and pingtests to get it fixed, sometimes you get bad IP with high ping, getting new IP 2-3 times can fix it most of the time, once in 15 days pings are high for 3-4 hours and it don't matter how many times you change IP. I had this issue 3 days in a row recently but it is very stable other than this.