I would say it's the exact opposite, you can see those alpha artifacts in Fidelity Mode (and on base PS5 after the latest patch) because ND removed/altered their TAA pass on the source they want to feed to PSSR.
OP screenshots must be from Fidelity mode because I haven't seen anything even close to those horrendous hair on Pro mode.
I mean:
This is the IQ and stability in motion especially compared to post patch non-PSSR is the thing that impressed me the most.
Your own screenshots show this, hair artifacts on Fidelity and not on Pro mode.
I really find hard to believe someone could have Pro mode in front of him on a good panel and not have the jaw on the floor.. there's a reason many considers it the most impressive Pro IQ along with Forbidden West.
No idea what TV you have nor your settings and viewing distance, but perhaps properly setting sharpness to not excessively interfere with the source and disabling any kind of filters and similar could help.