Invalid certificate errors are expected for people who use DNS resolvers which are still using the cloudflare nameservers.  It's been about 18 hours since moving to a new nameserver, ideally you would be updated already.  It only took about 4 hours to update on my PC using Google's DNS servers.  There's absolutely nothing I can do on my end to fix the cloudflare certificates, it's just a waiting game for your DNS resolvers to use the proper nameservers.