Big Sur / Can't open windows from finder properly, but works on terminal

Describe the bug
When I open a .tex file on MacVim from the Finder's level (just by clicking on a file), I get an error:

On the other hand, when I open the file form terminal, ie. mvim <file_name> it opens properly and every plugin works, as on MacOS Catalina. This strange behaviour emerged when I updated MacOS.

To Reproduce
As written above:

1. I open a file from Finder - error pops out and actually nothing works (just like it was disconnected from anything that is installed and configured by .vimrc)
2. When I open a file from terminal using mvim everything works as it should.

Expected behavior
No such errors, consistency between opening from terminal and finder.

Environment (please complete the following information):

• Vim version: VIM - Vi IMproved 8.2
• MacVim version: MacVim 8.2.1719 (up to date)
• OS: macOS Big Sur
• Terminal: GUI, Terminal.app

Additional context
It emerged after system update from Catalina to BigSur.
I have MacVim installed from .dmg file.

Inizia confrontando il percorso di avvio di MacVim dal Finder con il percorso da terminale di mvim, usando la differenza segnalata nel caricamento di .vimrc e l’ambiente MacVim 8.2 come base per la riproduzione. Conferma il comportamento su macOS Big Sur, quindi traccia il punto di ingresso dell’avvio della GUI finché lo stesso comportamento configurato non funziona dal Finder senza errori.