Hi there @mathews.boban ,
There are cases where the spring-loaded pin jams and is no longer connected to the brass plate, causing the petting system to stop working.
Please click the link below for more information regarding the EMO Petting System.
PETTING SENSOR PARTS AND SYSTEM
Petting EMO Tips and Tricks! (Images and Video)
I suggest carefully pushing the cheek area to re-push the Spring-Loaded (Pogo-Pin) slightly, But applying gentle pressure to prevent any damage.
Good luck and please let us know how it goes…