A gpu disappears

Consult, I have a motber ASRock h110 and a colorful, in both I tried to put 8 gpu 3070, 5 evga ftw3 and 3 zotac twin edge, start the hiveos seeing the 8 plates begins to mine well and after a while it turns off 1 Zotac, and it is running with 7. In both motber the same thing happens to me. And if I restart the hiveos it already starts with 7. Does anyone know what it can be?