The iOS app gives an error “Wrong path, file/folder doesn’t exist” when sharing an external folder where the folder name contains an ampersand (&). The external folder type is SMB/CIFS and we’re on Nextcloud 10.0.1. The Android app succeeds as does the Nextcloud web interface. It seems to be an iOS only problem.
aaarrrgghhhhh thanks @bness for you report, i create a bug on github for fix.