2 Answers

Just to let you know, we do look at these threads-- sometimes we have no real answer.. However. There's many things that could cause your interrupt,  Some devices although the say are 'bluetooth' are not compatible with other bluetooth devices, where the language is universal, the quality is not.  You might want to try a different device or cellphone to see if the results are the same. Problem could be cellphone or bluetooth device. No way of knowing without experimenting.  Is this bluetooth device integrated into your sound system in the tractor?  If not and its a bluetooth  earpiece, does this happen when NOT in the semi??   You need to isolate the problem.. It could very well be interference from your tractor..   Good luck.  The answer to any problem is to first isolate..  

Hope you will find some information from links.

https://www.squidoo.com/truckdriverondustry             (2)   https://www.buzzillions.com/reviews/over-head-n

(3) https://www.reviews.cnet.com/headsets/vxi-bluepa