I have an mkcert CA on my device - Is it possible to stop my device complaining when I access my home WiFi?

[sitebuilderai]

I have an mkcert CA on my device (Android) for local development and testing. However whenever I join my home WiFi I get an error about an untrusted certificate and do I want to trust the network. Once I confirm that I do, I can use the mkcert CA perfectly ok...until I leave the WiFi network and return or toggle it on & off - at which point I get a repeat of the same error.

Have I done something wrong in setup / configuration?

I don't recall this happening until today. I had a need to reset my device networking over the weekend when having some BlueTooth issues and it feels like it has been happening since then, bit this could be a red-herring.

Thanks