PAS/throttle work but speed/distance/battery display not working

[artvdelay]

Recently purchased my neighbors older Radwagon.  Not sure of year but the headlight is not integrated if that helps.  Probably a 2018. 

Anyway a couple of issues. 

Issue 1:  The controller turns on but the display does not change (always at 0) for most of the readouts while idle and riding.  The PAS assist and temp show accurately on the display but the MPH/Battery level/Watts/time/distance do not change.  Related is the display turns off after a few minutes probably due to timing out as it may not be getting feedback.  So the bike is functional (PAS and throttle work) but dont' know the speed and the display will turn off after a few minutes during the ride unless PAS levels are changed regularly during the ride.  Have tried replacing the controller as i thought there is not feedback from the motor/speed sensor to the controller. 

Issue 2:  The bike will glitch occasionally during PAS.  This feels like the battery power is dropped for a half second leading to a jerking motions while riding.  Not familiar enough with ebikes to know what is going on here.  I would guess that something is going on with the motor. 

Any advice is appreciated.