Microsoft Teams Connectivity Issues Using Sophos as Proxy(XGS 3300 )

We are experiencing an ongoing connectivity issue with the Microsoft Teams App when conducting online meetings in our organization. Whenever a meeting is scheduled and participants are invited, only the initially invited users can communicate effectively. However, when additional participants are added after the meeting has started, they are disconnected within a few seconds, with an error message stating, "Sorry, we could not connect your call. Make sure you are connected to the internet and try again" (screenshot attached). Additionally, these newly added participants cannot hear or communicate, and their status in the meeting remains as "calling." This issue is causing significant disruptions and impacting our productivity. We have already checked with our ISP, and the MS Teams App works fine on an open internet connection. However, the problem arises when we use the Sophos proxy. We would greatly appreciate your assistance in resolving this matter as soon as possible.