Blocks shouldn't disappear at 61 ping. You should probably talk to staff on Discord and they can help. Maybe you need to join through a different proxy? I was having the same issue a month ago even though I get 5-10 ping and 1200MBPS. The staff said they were working on it at that time but you should probably check with them
I myself is not experiencing that much lag in the server although I regularly get 120 ping. I personally do in fact think that the server lags sometimes but not always. I hope they are fixing this although I am not getting a very awful experience from the lag.