I have a wildcard certificate issued by Sectigo. The certificate was provided as a .p7b. I have converted it into a .cer, a .pfx, a .pem file and attempted to install it in the firefox certificate store in my windows 10 system. I choose 'import' and point to the .pfx file. It appears that it is working as I do not get any errors, but the certificate is nowhere to be found. I have checked all of the certificate choices in the certificate manager. I used mmc to see if the certificate was in the trusted root certification authority. It's not there. I finally installed the certificate successfully in the trusted root certification authority using mmc, hoping that that would allow me to install it successfully in the firefox certificate store, but I get the same results. I have run Firefox as an administrator, same results. I have googled over and over with the same results, i.e. it appears that the certificate is not installed.

How can I get this CA Certificate installed in the firefox certificate store.