Bought the wife one of the above with Sony WH1000 XM3s last year. Until recently pairing has been seamless, just worked. However recently the headphones have, from time to time, needed to be paired manually but, today they are refusing to pair at all. I assume the problem lies with the BT T100 as the headphones paired without issue with my phone today. I have tried deleting pairing information from the BT T100, as suggested by Sennheiser, and to be sure, from the headphones, makes no difference. Anybody got any ideas, other than transmitter kaputt?