The line was just short of a total meltdown this morning. Trains were running about twenty minutes late. Not a great look for introducing people to a new service, but hopefully things settle down in the next couple of days.
I'm not seeing much on the MBTA site, but word on the train was that it was signal issues. I would be surprised if it was related to Foxboro, but there were a lot of people unhappy about the changing schedule on top of the delays. My biggest concern would be this leaving a sour taste in people's mouths, but if literally anything goes wrong on that line the comments on the MBTA Rail app start professing damnation upon entire countries, so I don't think it's a major issue.T Alerts would have the location. Most likely a mainline or NEC delay, as there's only 5 miles total of track between Walpole Jct. and Foxboro Station. Odds favor the usual culprits overwhelmingly over the new route.