Found a new "edge case" - basically if an org folder is being created and then an empty repo added, it wont offer to create a Jenkinsfile in github. if the org folder already exists, then everything works as expected.
- Create an empty github repo - no commits
- Ensure your jenkins has no github org folder for what you are about to add
- Add a new github pipeline via blue ocean - and pick your empty repo
Note that it will "time out" and not offer to create a pipeline, only an empty org folder will exist.
If you then repeat the above, it should result in an offer to create a Jenkinsfile (ie the second time, it seems to work). Somehow the creation of the org folder the first time prevents somethign from happening that prompts the editor.
I am not sure if this is in the creation flow code or the editor though... hard to tell. It is probably not an uncommon case to come across.