@Kevin_Z Thanks for your response. I did have most of the items already checked from that list. The ones I did not were updating the firmware and changing the DNS/gateway. Neither had any impact....

I should also say the modem control panel shows a steady connection, which was the experience when connected directly to the PC.

I recently connected a Netgear LM1200 modem in bridge mode, and when connected to my PC it's fine. When connected to the WAN port of my A7, the router keeps dropping the connection saying WAN...