I didn't say anything was wrong with the pool...
When I check in open wrt, the avalon interface it shows a constant 6.8Th/s but the ckpool users page is less constant. Sometimes showing similar sometimes showing close to half.
You think there are intermittent times when only one miner is hashing? this seems to be a recent occurrence.
A minute ago all was normal....
The pool can only estimate based on your submitted shares which will not be submitted regularly enough to guarantee accurate reporting over a small time frame; only a long one. Usually the 15 min hashrate is the most accurate "short term" hashrate estimate.