I have a strange issue on my MacBook Pro (Mid-2017 15" with touch bar; MacBookPro14,3; 11.0 Beta (20A4299v)).
I've just installed macOS Big Sur on an external drive and everything was alright for some time. Terminal app was working perfectly and I still has one window open with it working OK.
The last step I remember doing was downloading and installing iTerm and adding it to the Full Disk Access on Privacy Control Panel before executing it.
After this, every time I open any terminal prompt, with the default app or iTerm, zsh, bash, etc., does not appear, and the window shows login "Terminal - login" and it does not show prompt.
NOTE: I know it refers to a beta OS but this problem has already appeared on other macOS versions. I tried the steps on both of these links but none solved it: