Exchange 2019 onPrem: Change rights on public folder ->Public folder disappears in Outlook favorites

Hello everyone,

we use Exchange Server 2019 on prem an public folders for a shared calendar and a shared contact list. Calendar und contact list are set as favorites in our Outlook (M365 Apps for business) clients.

When we get a new colleague, the new team member gets Publishing Editor rights on these public folders via Exchange ECP web interface, as everyone else in the team. 

After setting these rights for our new team member, some other colleagues complain, that the public folders disappeared in their Outlook client. 

Which colleagues face this behaviour seems absolutely random.

It seems like settings rights on public folders in ECP triggers disappearing favorites in Outlook. 

Troubleshooting is very hard on that behavior because it occurs randomly to colleagues. 

(Not sure this is the correct forum for my question). 

Best regards

Sebastian