I used to mount network attached storage in /mnt until I had problems accessing it from a Snap. In searching for a solution it was pointed out that snaps are correct in being sandboxed from these types of folders, and users like myself are making things difficult for ourselves by using those system folders.
They said the best practice would be to mount them in a folder in your home directory. I’ve switched to doing that and it works great.
https://github.com/jumoog/intro-skipper
I had some weird problems while installing this because I didn’t remove the other one first. I’d remove the confused polar bear one and delete the repository before trying to install this one, and do a restart or two so things figure themselves out.