Sol/s Much Lower Than Should Be/Varying Wildly

I’m mining with claymore on Flypool with an R9 270. I should be getting 170-180 MH/S, about 190 MH/S overclocked, which is what I got in the beginning of mining. However, the speed suddenly dropped to about 70 MH/S on claymore and flypool shows this:

https://zcash.flypool.org/miners/t1ZtgufaQ8MAh1oJF8U3TkzQBPHpk45UtuM

I don’t understand what’s going on, same issue without an overclock.