I got a few calls with same since 12.3
It seems to carry over from last rx. If you inactivate the med and start brand new rx it seems to reset.
We can't see this field completely but it's sent to newcrop or newcrop generates it.
It happened in 12.3 as part of a fix I requested to be able to send 3 consecutive controlled rxs at once 1 now and 1 for each of next 2 fills. It used to give a bogus rx valid date on 2nd and 3rd refills.
Definitely needs AC escalation.