Modem drops signal constantly

I have this problem, I used to get about 300 up but was paying for 1.3, a tech came out and replaced the line, at the time I got a message from xfinity to upgrade my modem which I did.  I got intermittent drops, using the modem in bridge mode, a tech came out and said that there were no disconnects and if it continued to try using the modem as a router as well, I was worried about dual not but I tried it anyway and still got drops.  So I put the router into AP mode to try that and its still happening.

I have service coming in to Xfinity modem to ASUS router in AP mode then onto the rest of the network.

Any ideas, could the router in AP mode cause a problem, I don't see how but I need it to go to the mesh system.  My wife and daughter both work from home and the drops always happen at the most inopportune moments .  As I said the tech says no breaks in the uptime but the app says that the modem is offline when the system drops.