Hd60s 1080p output has artifacting

I’ve run a test stream and there’s no artifacting on the output to my pc. However I’m getting artifacting on my tv that the card outputs to. Tried brand new hdmi cables, no change, tried bypassing my hdmi splitter, also no change. Set my switch to 720p in its output and it went away.
How can I keep 1080p without the annoyance of the artifacting?