One keyless entry door button not working all the time. ?

[mercmancdi]

Have a 2017 glc keyless entry but just discovered the rear drivers button to open door keyless only works now and again on this door all other doors perfect.
Any suggestions

 

[mioba]

Scan the codes. Probably the sensor at that door.

 

[mercmancdi]

Yes can do , funny thing it opens keyless but won’t lock its push button thinking fault in button.
It’s not a major problem as long as no other doors start to follow.