From searching through ACARS logs N652UA flew UA929 LHR-ORD on Feb 9 and also UA9915 ORD-GSO on Feb 17 with no ACARS logs captured in between in the sites I searched. And none since Feb 17, so it appears to be in GSO getting repairs.

Not all flights will show up via ACARS searches but this fits in with the OP mentioning it may have happened on Feb 10.