I'm doing a from-scratch jenkins install, latest version.
Setting up a github org folder.

It is doing a scan.

It has gotten a hundred or so repo/branches in, and

Checking branch  xyz ....
21:35:56 Jenkins-Imposed API Limiter: Current quota for Github API usage has 6875 remaining (1 over budget).
Next quota of 12500 in 40 min. Sleeping for 26 sec. 
21:35:56 Jenkins is attempting to evenly distribute GitHub API requests. To configure a different rate limiting strategy, such as having Jenkins restrict GitHub API requests only when near or above the GitHub rate limit, go to "GitHub API usage" under "Configure System" in the Jenkins settings.

Okay thats great, but.... while this is running, it is stopping the MAIN SERVER from processing normal web requests?

Attempting to just load the main jenkins page, times out.

technically, we are running it behind an NGINX SSL proxy, so we specifically see

504 Gateway Time-out

nginx/1.24.0 (Ubuntu)

—
Edit: in case you are wondering, yes a simple

curl http://localhost:8080

just hangs indefinitely on the local server