I have a lot same problem but only when i close a windows or change algo ... it's strange ...
Contrariwise i have no problem when the hdmi is plugged in motherboard ...
What is your model evga card ?
Gigabyte AORUS 1080 Ti cards.
@philipma1957
Efficiency is not everything. While you lose out on some efficiency on 100% power limit or even higher, you earn more.
Besides, setting cards to 100% doesn't mean they will always use 100% power, most algos don't go anywhere near that, more like 70% but for some power hungry algos it allows the cards to eat more and produce more.