Software version?
My 2021 model 3 LR AWD and my wife's 2021 model 3 LR AWD are on 2021.4.15 with no issue opening the manual. I just tried it on both. It's still the old 2020.44 manual just like on the Tesla site.
I'd absolutely do a hard reboot (hold both scroll buttons and brake).
It may be overkill but after every software update, I do a hard reboot. Save headaches in the long run.