Activity app doesnt show changes in external mount storage shares by upload

Nextcloud version: 18.0.0
Operating system and version: 19.10
Apache version: Apache/2.4.41
PHP version : 7.3


when you share a folder on an external mount storage (smb, ftp) and an external person uploads some files the activity app show no changes.

When you share a folder localy on the nextcloud storage it works and in the activity app u see the changes.

i tried it with smb and ftp. Same effect. Did somebody have the same problem and a solution for it?