I operate 6 nodes to support EAC network and there are 3 different block heights on them.

Compare the block heights on teh block explorers

https://chainz.cryptoid.info/eac/
http://explorer.newearthcoin.com/
http://212.237.21.74:3000/
http://120.79.171.136:3000/

I identified the source of the disruption as so called "time travel attack". One of mining pool has adjusted system time to +10 minutes, so the blocks mined by this pool (that one with the EAC address epQSyjK3XyJVEEk1xwuxekrbzty92jynSF) decreases the difficulty. This leads to an increased count of blocks extracted per hour without increasing of the difficulty. Some of nodes do not accept such a manipulated blocks so they lost sync.

My suggestion is accept the block height from the primary explorer https://chainz.cryptoid.info/eac/
and do a softfork from this checkpoint.
But for an action I need the agreement from the comunity.