GZunit
Are you using your PS5 to watch streaming platforms on your TV?
I've also had a strangely okay experience with a PS5 + a modern TV as well (a LG C9 in my case, a 65" OLED TV with WRGB stripe subpixel layout. It has mild "brightness dip" flicker on every frame but no strobe-like PWM. There is also a Sony surround sound receiver that also serves as a HDMI splitter in-between the PS5 and the TV, if that changes anything).
This is essentially one of the only modern screens I can actually enjoy a show or video game on. Not as good as my "truly good" screens and get some mild strain, but I can still say I'm able to fully enjoy an episode or two of a show each week, or get immersed into a game for about an hour and 30 minutes every now and then before feeling like I want to stop playing.
However, the same LG OLED TV is totally unusable and causes a ton of eyestrain with an Apple TV 4K connected though, on the Apple TV I can't follow anything that is going on in a show or its plot at all (including the same shows that look decent enough to enjoy when streamed via the PS5). Everything feels like a blur to me with the Apple TV and I have to refocus my eyes every single time the scene changes.
The OLED TV is only enjoyable for me when connected to a PS5 (even though both inputs have the exact same settings, each device has the same output formats selected in their own settings, are connected to the same receiver, and I've tried the same HDMI cable.)
The 2017 Nintendo Switch is also uncomfortable and strainy when connected to this TV, although I feel that's for a completely different reason than why the Apple TV 4K doesn't work -- the Switch only supports 1080p output so it is likely activating a ton of additional upscaling and processing functionality on the TV in order to scale the image to 4K, which the PS5 doesn't need.
The Nintendo Switch is much more playable when connected to much older TVs like my 2004 LC-G5C26U Sharp VA TV. Although, the Switch still certainly has some GPU-related issues -- because it's not as comfortable as connecting a "truly safe" output to that old 2004 VA TV such as my 2011 Raspberry Pi 1 Model B
(which is on a whole different level of comfortable compared to everything else I'm discussing in this post, LOL. That Raspberry Pi is essentially 100% strain-free when connected to the 2004 Sharp VA TV, one of the best ways I can VNC connect into another computer for hours of serious productivity and comfortable reading, etc!!)
In my case, HDR is off though and every single post-processing setting on the OLED TV had to be turned off in order to make it "OK enough" for me with the PS5. Interestingly, the LG OLED has a "4:4:4 passthrough" option that claims to disable many forms of extra post processing that the other settings usually can't control, and I feel that this setting is what led to the greatest improvement for me with the PS5 and this TV.
However, although the PS5 has been surprisingly playable on this TV, I will say that there is still some temporal dithering (coming from the PS5 as it's not present in the TV's own menus) that I see when looking up close at the OLED subpixels.
Overall though, it is very fascinating to me that I can play and watch shows "good enough" on the PS5 with this TV, but not at all when the Apple TV is connected…
BTW, the OLED TV is still on the original firmware it shipped with, and has never been connected to the internet so it has never received any updates. The PS5 and Apple TV are on their latest versions though, and are updated frequently.