Hi
@djry,
This happened to me after a longer than expected holiday in Mexico. Couldn't get my levels down but put that down to stress.
I woke up one morning, about a week after getting back (using the insulin I'd taken with me) and felt awful. My ketones were through the roof and I had to be admitted to hospital.
My DSN couldn't be sure but did suggest it could be due to the insulin I took with me expiring due to heat/altitude so told me to throw any bottles of insulin away that I'd brought back from holiday.
I hope this helps. My only other suggestion would be if you are feeling unwell or aren't quite back in a routine yet?
Keep testing and check your ketones