Struggling with Android permissions

Using Ubuntu 18 and with android s9 and cannot seem to get it to sync. Trying to sync to a mounted drive and continue to get messages that say that it cannot create folder. Looks to have the right permissions, so not sure what is going on. There is a syncthing group with access. Any ideas please?

It’s not clear which device on your are having permission issues.

Assuming mounted drive means microSD, then unless you use custom ROMs/root there’s no way for Syncthing to access that (see https://github.com/syncthing/syncthing-android/wiki/Frequently-Asked-Questions#what-about-sd-card-support).