I agree!! From July 11 thru July 16th I got the following ZEC payments (rounded):

0.096
0.085
0.049
0.058
0.036
0.249

I look at my payments daily and noticed this downward trend.  I was thinking maybe the difficulty went way up or something (i.e. Bitmain running their new Z9 "max" before shipping them in September ).  However, I checked some mining calculators and saw I was getting WAY lower than I should be for the hash rate I was at.

So I immediately moved off Antpool for ZEC and went to FlyPool  https://zcash.flypool.org/ - never used FlyPool before but figured it all out - pretty easy. 

In about 21 hours of mining I have around 0.12 ZEC on FlyPool.  More like it!

Maybe Antpool was having some issues??? OR just taking ZEC from us???