This issue happen to me after I deleted the first and original branch (master), that was created by DevOps.

I had already successfully created a CI pipeline from the repos. When I returned to create a CD I experienced the issue described, 'No matching repositories were found'. The only plausably related action I had taken was to create a 'main' branch of 'master' and then delete 'master'. In essence, to try rename 'master' to 'main'.

After this I created a new repository, with the first source branch 'master' intact, and this issue didn't occur.