I confess - I neither have a PS5 nor understand, really, the nuances of VRR and such.
That being said, would it be worthwhile to see if disabling (and then re-enabling) VRR on the Spectrum when connected to a PS5 makes any difference?
From reading this excellent discussion, I’m inclined to say “No, because that is what locks the refresh rate in the first place.” However, at least one user elsewhere reported that … AdaptiveSync (on DP connections) was not working until it was disabled and then re-enabled.
Just a thought. I suspect not, as @ReignDespair mentioned above that it is not supported at all on the PS5 … but it can’t hurt to try, right?