Cisco VPN and App Calling issue

I am relatively new to the remote worker role and am running into issues with VPN, Poor speed on Speed tests, and inability to make calls in the Genesys App. I have found little support from anywhere other than reading the entries on this community blog. I exchanged the T-Mobile modem for the upgraded version. They gave me 5G Gateway Sagemcom; The connection was immediately much better. I used the instructions from another customer to change the network settings, and the VPN connected with no issue. When I performed the company speed test, it was still slower than their recommendations. Any tips on boosting these speeds? Does anyone know if this will improve the App calling function within the system? And if not, any guidance on that aspect? I am like others on here, and the system was working fine until last week; there was an overnight loss of the ability to make calls through the company system. The customer can no longer hear me, and I assumed this was related to a change in the VPN connection and speed. A lot to unpack here, but in a make ii or break it mode.