There is an old bug report on Travis I nechroed about six months ago about a bug the Travis people said did not exist but was actually proven to exist.
I am wondering if this may be a cause.
See comments from @rajsite about half way down page.
Note: This is why I had made a Travis.yaml edit about six months ago because I had already tried the suggestions made before finding this report and nechroing it.
When testing this on my clone of the wiki I saw this under Settings/Integrated Services.
Note: GitHub Services are being deprecated. Please contact your integrator for more information on how to migrate or replace a service to webhooks or GitHub Apps.
It is not related but just a heads up.
I just tested my personal unlinked clone of the wiki and everything worked perfectly and has the same settings as the current wiki.