It appears a combination of 60Hz and low latency mode being enabled causes my display to flicker, this happens both through USB-C to my Mac and HDMI 2.1 with my PS5.
The flickering is not “in your face” obvious but it’s worse than a subtle flicker (which the display shouldn’t do anyway). I’ve noticed it doesn’t happen in Quake remastered at 120Hz and in macOS at 144Hz, but the infuriating thing is most PS5 games run at 60FPS/Hz.
I’m still on firmware 102 due to not having a Windows PC available to upgrade (actually I tried my wife’s ancient laptop but the firmware update fails instantly). I’m at the point now I may just buy a cheap mini PC/stick from Amazon, do the update, then return it But I don’t see anywhere in the 104 firmware info about it resolving a flickering issue at 60Hz with low-latency mode enabled.
Video: Spectrum Flicker - YouTube