Hello everyone, first post here so please be gentle!

I just recently got myself set up with a Pepwave Soho MK3 for a home network. So far I am pleased with it, as it does most everything I want it to do; credit to the development team. However, I have one moderate issue I am not sure how to resolve despite some middling technical experience.

I currently am using the Soho to act as an access point to a second router via Wifi-WAN (in addition to providing local LAN and wifi routing to other devices). I do not have admin access to the second router, unfortunately, and it is the one providing an internet connection.

Everything is working great for my local devices except that when I connect to certain sites via a web browser (firefox), I get “SEC_ERROR_UNKNOWN_ISSUER” errors. This does not occur when I connect to the source wifi directly and try to access the same websites. (Common examples such as youtube.com, gmail, etc).

I can access the sites fine via the Soho-provided AP if I bypass the certificate warnings, but obviously this poses a security issue, and I do not understand what is happening to cause trouble with received certificates.

Can anyone advise me on whether/how I can set up the Soho to resolve this issue? I have been examining the configuration pages and looking up features, but I have never run into this problem before. Thanks in advance.