I have a Ryzen 5 1600 @ 4 GHz paired with a, OCed GTX 1070 Ti and 16 GB of DDR4 @ 2933 MHz. FPS drops happen especially when I look at match details (to check if I have gold medals).
I get the same problem recently.
150 fps until a fight and then 90s
Specs are:
i58600
GTX1080ti
16GB 2400MHz DDR4