Nicehash is red hot right now and they may be switching you around a lot.

Which can screw up a miner.

you could try to set a level in the password so you dont switch as much.

but going to viabtc and setting to pps+ is a better way to see if you have an issue.

as nicehash could have a problem due to a hot bs coin.

you may have a voltage sag issue if you have a lot of xxx and oooo.

the voltage needs to be high enough for an apw3+ like 205 to 240 is better then 190 to 210