How can they not reproduce the issue however? They have access to our characters, the exact data stored on the servers, and the ability to roll it back.
So make a copy of the character with the reported issue before they TR/LR/GR, and use that as the test bed to figure it out.
If they still can't make that work, that means there is some client timestamp data that is corrupting everything.
And if QA hasn't done this sort of test yet... well... they need to start doing so.