JIRA Cloud integration fails with SSL verify fail

I am unsure of which template to use. If I did it wrong I'll happily correct it.

I've set up a brand new VM server with CentOS 8 and the newest GitLab CE (FOSS, apparently). All works perfectly. I have a official wildcard SSL certificate that works on various other servers and the chain is 100% correct. For some reason when I try to add our JIRA cloud the UI doesn't provide much more insight than "Connection Failed". Thankfully I am somewhat experienced in this area so I quickly found the error using gitlab-ctl tail.

The error is quite clear, it says it cannot validate the certificate for our JIRA Cloud domain.

{"severity":"ERROR","time":"2021-03-09T17:57:34.338Z","correlation_id":"01F0C263AEV3VYQ4271AGEMB7S","service_class":"JiraService","project_id":2,"project_path":"X/X","message":"Error sending message","client_url":"https://X.atlassian.net","error":"SSL_connect returned=1 errno=0 state=error: certificate verify failed (unable to get local issuer certificate)"}

I tried everything I could think of and find. I found that I could add the right folder for verification as such: gitlab_rails['trusted_certs_dir'] = '/etc/pki/tls/certs'

No cigar.

Additionally, I tried regenrating and adding the certificate I could retrieve using openssl from the main atlassian domain. Adding that in the right folder and force-enabling the update-ca-trusts file did nothing as well.

I am at a loss as to what is going on.