have an RV130W router, about 2.5 years old, last firmware update.
The main internet signal is passed through from my cable modem that is setup as passthrough.
Multiple times a day, I will hit various web pages and the page will tell me there is either a certificate error or a certificate problem. This happens on multiple machines, so it's not a machine issue. Also, if I take the cisco router out of the network and plug directly into the cable modem, I don't see these problems.
I do still see the problems even if I'm connected via hardwire to the Cisco router.
Any ideas on what I can check here?
"the page will tell me there is either a certificate error or a certificate problem"
this is phrased incorrectly, it is your browser that gives you this message, not the web-page retrieved from the server.
check if you are using the same nameserver when using the Cisco as when using the connection direct to the modem
check your time-sync when using the cisco router
in your browser open the certificate details and look for hints why this is seen as a problem.
what browser (Chrome, IE) are you using, and do your machines have any security software running (and if so, which) ?
I use all browser types, Chrome, Edge, Firefox. Once I see that error in one browser, it shows in all browsers.
We use Windows Defender for anti-virus and log in to Azure Active Directory for authentication.
The issue is most probably due to time/clock mismatch. Please check time/clock on your all networking devices. Due to time/clock mismatch certificate is not getting authenticated by the web server.
Recommendation is that time/clock should be same and real-time in the network.
Further you can configure a NTP server in your network to avoid the issue.