Video conference issues with a VPN

I have a customer that works for a bank. Everything she does on her computer goes through their VPN. Up until recently she never had an issue with any conferencing. Now that I switched from fiber back to a cable modem, she seems to have issues using teams, zoom, she’s being disconnected after a few minutes. I’m stumped as to what could be causing the issue. I’m waiting for a new white being 5AC Gen 2 to come in to replace the old light beam Gen 1, I don’t know if this is the issue or not I’m not seeing any packets dropping or any connectivity issues normal speed test to the internet showing 75 megs at 20 ms down and 31 up at 20 ms. I recently installed an Edgewater x in their home along with and already installed ceiling mounted access point I don’t remember what brand… I’m wondering if there’s some sort of QOS that I can set up for this particular customer. Any suggestions?