Employer's VPN suddenly started dropping every few minutes

I've been working from home on my company's VPN for a couple months now.  In the last few days the connection has become very unstable and disconnects and reconnects every few minutes.

My CM1000 cable modem is from Xfinity.  My wireless router is not from Xfinity - it is an ASUS RT-N56U.  I updated the firmware in the router to the latest version 2 days ago when I started having this problem

I connected my laptop directly to the router with an Ethernet cable and disabled the wireless.

I'm still having a problem of the VPN dropping out every few minutes.

Xfinity troubleshooting says everything is fine when it looks at my system.  I have had it reset the cable modem a couple times. It doesn't really have an option for exploring intermittent connection problems like this.