I own an Alienware AW2518HF 240Hz monitor purchased on August 6, 2018. This monitor says that it supports up to 240Hz, which includes 120Hz at 1080p. However, the PS5 can only recognize 1080p at 60Hz. I have read in other places that this may have to do with FreeSync being enabled, but I am not sure if FreeSync is normally enabled by default if not plugged into a PC (i.e. if its hardware enabled or software). In any case, I think you need to put out a firmware update (if that is even possible for this model?)
@GTS81 Its one thing to ask to get their monitors to work, its another to get verification whether something works or not if its advertised as being compliant for a specific HDMI version and a given framerate. I spoke to something and they said that their verification process is only for Windows with specific drivers. Any other system, device, or receiver is not verified to work with the Dell monitors. Other monitor manufactures have at lease gone out and confirmed that theirs can work, for example the BenQ EX2510 does.
Sony has not announced that the PS5 will/does support Freesync. My understanding was PS5 was going with HDMI 2.1 VRR (in lieu of Freesync), which I don't think has even been rolled out yet on the PS5. Note also that this monitor has HDMI 2.0 ports (not the HDMI 2.1).
Hey man did you figure it out ive also tried everything and starting to feel like I wasted $370 I just bought this monitor specifically for the PS5. I didn’t think it be this much of a headache.
How about setting both the refresh rate and 4k transfer rate to auto, under video output in the PS5?
Even with an AMD gpu, there's like pretty much no chance of getting AMD freesync to work on the PS5 without support from Sony (which hasn't been offered yet at this point, and no plans other than hdmi 2.1 vrr announced for the future, but anything is possible). Anyway, this is all beside the point, as that is actually a different issue than the question of how to switch from 60 to 120 hz.