Microsoft Teams: Could not read the contents of FOLDER?

I am using Ubuntu 20.04 and I've installed Microsoft Teams using Ubuntu Software.

When I want to upload a new file to Microsoft teams that is on a different SSD I get the following error:

Could not read the contents of backup
Error opening dictionary '/mnt/backup': Permission denied

I've mounted the drive using the following line in /etc/fstab:

/dev/disk/by-uuid/6fa6ae01-fcd4-4771-a89d-cffa9744d630 /mnt/backup auto nosuid,nodev,nofail,x-gvfs-show 0 0

When using Firefox it can upload files from the mounted drive without any problems.

Has anyone any idea how to fix this?

Edit:

Tried the snap connect some-snap-name:removable-media command:

error: snap "teams-for-linux" has no plug named "removable-media"

Edit 2:

Also tried "Microsoft Teams - Preview". Unfortunately the same problem.

error: snap "teams" has no plug named "removable-media"

Edit 3:

Also tried "Microsoft Teams - Insiders". Unfortunately the same problem.

error: snap "teams-insiders" has no plug named "removable-media"

According to the search on Repology and then in AUR - MS has deb-package of the Teams application.

So you have to remove Snap based version and then install deb-version with:

cd ~/Downloads
wget https://packages.microsoft.com/repos/ms-teams/pool/main/t/teams/teams_1.4.00.13653_amd64.deb
sudo apt-get install ./teams_1.4.00.13653_amd64.deb