Problem with skype on checkpoint

[Arturxr]

Not so long ago we had a problem with skype with users behind our checkpoint. When going to the invitation link, we do not get a window to choose whether to enter as a guest or enter, together with the error in the browser "problem with your link", also can not create or join a meeting through the web version of skype or the application on the PC.
At the same time, bypassing the checkpoint, on the same PC we manage to go to this link.
Can you tell me what settings we can check?
We tried different browsers. we watched the traffic in z debug, tcpdump, made exceptions secure xl, https inspection exception, bypass, but nothing helped and in the logs we don't see any traffic blocking

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[Arturxr]

This is a screenshot of our window when clicking on the link

Skype

The problem with your link

Sorry, there is a problem with your link.
Check it and try again or ask a friend to send you another link

[G_W_Albrecht]

? As i wrote above: I would suggest to contact TAC to get this resolved asap !

[G_W_Albrecht]

I would suggest to contact TAC to get this resolved asap !

[PhoneBoy]

Are you talking about Skype proper or MS-Teams?
Either way, start with some basic information like:

• Version/JHF of all relevant components
• How precisely are you "allowing" the traffic in question (what Access Policy rules are involved)
• What other blades are active besides HTTPS Inspection?

Of course, if you want a quicker resolution to this, it might be worth a TAC case.

[Arturxr]

I'm talking about skype.
-81.10 jhf 30
-Did anything from PC to PC
-HTTPS Inspection we have disabled, firewall, aplication control, url filtering, ips, antibot, antivirus, monitoring active

[PhoneBoy]

Please describe the topology when the gateway is present versus not?
I suspect this isn't a gateway issue but an application/routing issue.