Microsoft Teams not working in browser with invite link

[M-Polo-n]

We are encountering a somewhat strange anomaly, from many computers, sometimes it happens that after clicking on the link to access a meeting / call, the browser loads the address but then stops after a few seconds. This happens randomly. On PCs where we are carrying out tests, sometimes the same link works on a PC but after 1 hour, with another link it does not work and crashes.

We have a fortigate 900D, 

we have the rules set up to manage teams and skype traffic using the presets already included.

thank's all.

[M-Polo-n]

update this post, in the firewall rules, there is one that blocks traffic to microsoft update. disabling it, Teams returns to work. The problem is figuring out how to make the rules coexist.