MK2I + Transmitter: problems of connection underwater

Hi all,

I was diving in Mexico this summer (36 dives in total) and I experienced issues receiving data from the transmitter under water. Battery on the transmitter ended up being low and then empty after roughly 70 dives (seems very few to me). I have the transmitter on a small flexible same side as I am wearing the watch. I did not have that problem before that diving trip with the transmitter directly on first stage and opposite side. I changed the battery and got a better signal but still with errors in data reception (air level and instant consumption) from time to time. 

Also, I haven't been able to update my watch because it can't connect to a Macbook USB C cable (I have followed the procedure for fixing the issue without any success).

Has any anyone experienced the same problems? Got an answer for Garmin? 

Many thanks in advance!