DROPPING OUT BUT NOT RE-CONNECTING

I have had the router fot just 18 motnths, without any issues. A couple of months ago I noticed my interent connection had dropped. I turned off the router and a couple of minutes later turned it back on. Reconnected and back to normal service.

This started happening on a daily basis. I connected a spare router and the issue stopped. Swapping routers every weekend got the same issue. Netgear router drops connection within an hour or two and does not automatically reconnect. Spare router works wothout issue all week. Checked with ISP and they cannot see any issues.

The question I have is has anyone else had this sort of issue and if so, can it be fixed? I have the latest firmware loaded and it is NOT a wi-fi issue. Will a factory reset be a possible way to potentially sort it out?

Any ideas or help appreciated.