2 Gen Tundra Platinum Ultrasonic Sensor Retainers

I recently replaced my front chrome bumper on my 2013 Tundra Platinum Crewmax.
I've had two issues in doing this and both are related to the parking sensors. One is the sensors periodically beep with no objects in front of the truck. The second is the retainers that the sensors fit in to and mount are a pain to remove/install causing retainer damage.
Regarding the beeping, I first assumed the retainers were distorted or broken from forcing the fit into the bumper (causing sensor distortion or interference).
I ordered new retainers and confirmed the outer diameters of the new and the original retainers are same (1.0"). I checked and confirmed the new bumper, and the original bumper had the exact same hole diameters where the retainers install (~0.85"). So, I found that my original install issue was going to be repeated without guidance.
Any idea how a Toyota body shop installs new retainers in the chrome bumpers?

I had previously tried warming the retainers hoping to squeeze them into the hole. I also tried compressing the retainer to fit, but this only crack the retainer.

Maybe Toyota changed these on the 2.5 or 3rd gen Platinum's/1794's.. ??

Regarding the annoying beeping, if it's not the retainers then what? I've check and re-checked the connectors, I've cleaned the sensor surfaces, I've ensured the sensors are not loose and they're not.. running out of ideas.