I have 2018 Pivot Shuttle with Shimano XT di2 setup. Recently the bike started not shifting consistently, instead beeping. after a few jabs it would shift. This condition progressively worsened to the point it will not shift or display the gear position. I have checked all di2 tube connections, swapped di2 cables, completed RD reset, updated to the latest software, done a derail check. On the stand we can get the bike to go thru all of the gears but as soon as a person puts a load on the bike it stops shifting. Pivot and Shimano have not been able to help other than to say take it to a dealer. I am using the dealer tech to do all the updates already. Next step is component replacement starting with the shift switch, derailuer and computer. Bike has 4600 miles.