.org to .com migration - no repositories found

I’ve been successfully using travis-ci.org for a number of years on my GitHub project.
Although my master branch does not have a .travis.yml, other feature branches do, and these were working up until Travis CI disabled all GitHub events for .org.

I logged into .org yesterday and could still see my repos and build history (but now, no longer, post-migration). I did the migration to .com and I authorised the Travis CI app in GitHub.
In my GitHub settings, I have provided repository access to Travis CI, choosing ‘Only select repositories’, specifying my repository, and not ‘All repositories’.
I can confirm the Travis CI integration is recognised on the GitHub side. In the repository settingsIntegrations, Travis CI is present under ‘Installed GitHub Apps’.

However, in the travis-ci.com dashboard, I am informed:

“No active repositories could be found”.

I’ve double-checked that the .travis.yml file is present. My repositories are simple, and I’m not using private repos or the Travis API.
I’ve since made commits to the branches and pushed the changes to try and trigger Travis CI into action since the migration, in the hope this may show the repositories in the dashboard.
This didn’t work.

Following other suggestions and more recent solutions, I’ve tried navigating to the plan page, but I received a 404.
I realised this is because I need to prepend “app” in the URL, and can only get to the plan page this way instead.
According to the app Plan page, I am already on a Free account.
My app Account page informs me:

"We couldn’t find any active repositories you have access to.
You can add repositories by clicking the “Manage repositories on GitHub” button above."

When navigating to the ‘Migrate’ page, I see the following:

I proceeded to sign up for the beta, but am still waiting for any of my repositories to migrate across. Are there any additional steps I should be taking?

The documentation on having to jump through these hoops is a train-wreck.