Issue Summary

Jira DVCS connector is not compatible with numeric/alpha-numeric project keys 

This is reproducible on Data Center: yes

According to this documentation:

In all cases, the issue key must conform to the default Jira key format – that is, two or more uppercase letters ([A-Z][A-Z]+), followed by a hyphen and the issue number. For example, ABC-123.

In the meantime, Jira allows to use numbers in the project keys. The above limitation makes it impossible to integrate Jira (having numeric project keys) with GitLab

some more info from GitLab forum: https://gitlab.com/gitlab-org/gitlab/-/issues/27052#note_1904412080

Regex pattern is hardcoded in the code and there is no way to adjust it in any way. 

Workaround

There is no workaround for parsing git commits/branches/PRs messages.