PMP450 clients running PPPoE stop passing data

I am now dealing with a second customer reporting the same issue. Customer has a PMP450b High Gain SM, PPPoE and NAT running on the SM.

On the surface all loks well, the wireless uptime is high as is the PPP session uptime, however the customer reports that they intermittently lose internet access to devices inside the home.

A ping to the WAN IP of the SM doesn’t show any dropped packets. This has been the same on both 21.0 and 20.3.1.2

Has anyone else encountered this as this is the second time I have seen it now