Web-Addins stopped working for Office apps version 16.100 for Mac

Dear experts,

Since version 16.100, the web add-in functionality has stopped working with the Office apps for Mac (PowerPoint, Word and Excel). In may case, Templafy web add-in is not being loaded.

According to Templafy's support page: https://support.templafy.com/hc/en-us/articles/29028257609501-Templafy-Web-Add-ins-no-longer-accessible-on-Mac-after-Microsoft-Office-update-16-99 this seems to be a bigger issue. Clearing web add-in cache or deleting the WEF folder will not resolve the issue. I have also tried with a full clean uninstallation of Office365 apps and re-installation, same issue.

Note that New Outlook for Mac is not affected, just PowerPoint, Excel and Word.