CANbus troubles... The most unreliable 'bus' I've ever had to deal with in 5 decades of 'putering....'
What you can try is...
1st disconnect battery,go have a coffee...
now... remove/reinstall every CANbus. connector to every CANbus device 3 or 4 times, Examine that all the pins are clean and secure. Some (lightly) dilectric grease should be on them.
check EVERY 'ground wire' that is IS solidly screwed into the steel
check that all CAN wiring is secured but not tight(can't flop around but not 'noose' tight)
check/confirm that all 'computers' are SECURELY bolted to the frame/dash/wherever
after you're pretty sure you've done all this, THEN reconnect battery, cross fingers, turn key....