Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
Using www.ultraarena.com to access your site (using SNI) it serves an invalid (expired) certificate and is covering ultraarena.com and www.ultraarena.com domain.
Using any domain without using SNI, your server returns the default certificate for your server and it is the invalid (expired) certificate.
$ echo | openssl s_client -connect ultraarena.com:443 2>/dev/null | openssl x509 -noout -text | grep -E '(Before:|DNS:)' | sed "s/^[ \t]*//"
Not Before: Dec 17 19:23:51 2017 GMT
DNS:ultraarena.com, DNS:www.ultraarena.com
If you only want a certificate covering ultraarena,com then you are done, there is no problem, if you want to cover also the www subdomain you should review how you issued the certificate and re-issue the certificate but selecting both domains (with and without www).
The thing is I made it so that all traffic redirects to https, and when I try to reissue the cert it only lets me choose ultraarena.com it doesnt let me add www. and I cant quite find a guide
Please show also the output of the command certbot certificates.
I assume you issued multiple certificates covering one domain name and did not deploy them correctly in nginx.