Arrived at MAN from LHR on BA1402, on Wednsday 13th September. One bag turned up, the other didn't.
On Saturday 16th, tracking the AirTag inside my bag, I found out that my bag was being held in a store in an industrial estate on the outskirts of Manchester city centre. It was still there on Monday 18th, and finally delivered that afternoon – just short of five days after my flight arrived at MAN.