Forum login can be super stubborn, we mention this pretty regularly and it doesn't seem to have improved over the years. It varies for me but isn't confined to any particular browser or OS. Logging in on my Quest, 2 nights ago was impossible but worked straight away last night.
But yeah, I think even your AI would advise against re-installing Windows for this problem!
Intel 5820K OC@4Ghz, Titan X (Maxwell), 32GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v20H2 (19042.964)
I've never sat down to actually analyze what's going on but... it seems "to work best" if you first log into the main Oculus site; click through community --> Forums, and then wait 5 seconds for the "cross-site cookie shenanigans" to take place. Once that occurs, setup your browser to never clear [*.]oculus.com and [*.]oculusvr.com cookies; so that you stay logged into forums.oculusvr.com as the expiration for the forum login cookies is several months.