Door lock touch sensors does not respond
 

Just got a 2015 ES 350 (17k miles) in excellent condition. its a chrome package which has JM Custom Creation chrome mesh grill and chrome wheels along with chrome handle. i noticed the touch sensor do not always work when i try to lock via touch sensor. It'd would work once in awhile but not always (99% of the time it does not work) and this is with all four doors. i replaced key fob battery but still no luck. Car does have chrome cover installed on the handle bar so not sure it it interfere with the sensor. the chrome covers are made of plastic

Any idea or suggestion, anything i can try to get it to work.?