Speedo randomly dropping out

I have a 2011 Mack cxu613 w/MP8. I am having an issue with the Speedo randomly dropping out which cuts power. If stop & kill the truck & wait for all the instruments to turn off then start back up the Speedo then works until it randomly does it again. The fault light does not come on. If you are going down the highway when this happens I can just turn the key off until all instruments turn off then turn back on & it returns to normal until next time.

Very random - 5 minutes, 15 minutes or maybe even 45 minutes apart. Replaced speed sensor and speed sensor harness truck been to 5 shops no one can figure it out couldn't get up to 45mph loaded please help me