I looked at the logs, and this confirms my feeling. There is a
HTTP 401 Unauthorized error, which means there is an issue with the token you specified on your project:
2018.07.31 15:22:53 INFO ce[AWTwgWT_8jHLMyTQVLD5][o.s.c.t.CeWorkerImpl] Execute task | project=interaction | type=REPORT | id=AWTwgWT_8jHLMyTQVLD5 | submitter=AWTvERTnGEjsfxbZAp0n
2018.07.31 15:22:56 WARN ce[AWTwgWT_8jHLMyTQVLD5][c.s.b.p.v.VstsPrFacadeFactoryImpl] Failed to access VSTS, the repository or the Pull Request: API resource location xxxxxxx is not registered on https://xxxxxxxx.visualstudio.com/. HTTP 401 Unauthorized
2018.07.31 15:22:56 INFO ce[AWTwgWT_8jHLMyTQVLD5][o.s.c.t.CeWorkerImpl] Executed task | project=interaction | type=REPORT | id=AWTwgWT_8jHLMyTQVLD5 | submitter=AWTvERTnGEjsfxbZAp0n | status=SUCCESS | time=3615ms
Note that we are planning to improve this situation so that you get this kind of warning right inside the web application and therefore you can act on this. See MMF-1244 for more details about this upcoming improvement.