New gos device app store error

I am trying to install all apps needed on a new device but when going to the grapheneos app store I am getting this error.. Any idea?

Javax.net.ssl.SSLHandshakeException: Chain validation failed

Just to add. I am on a VPN if that matters. It didn't on previous phone

Changed time to automaticly and it worked. Its kind a worrieng that you are forced to do that to be able to have it working