ST Cruise Control Difficult to Set

This is a new problem. The bike has performed flawlessly for the previous 16K miles.
2013 STS. SM5.
In the past few rydes the cruise control has been acting strange (erratic).
It will turn "on" with the right hand grip slide switch.
When I push the slider down to set the speed, the indicator in the instrument cluster,
briefly flashes green "Set" and immediately reverts back to showing "On" in black and white.
The cruise doesn't turn off it just refuses to set. After a few miles of fiddling, turning off/on and
reengaging the system SOMETIMES works.
I lift the brake pedal with my toe and push outward on the clutch lever with my gloved hand. (ATGATT)

I'm thinking a finicky sensor.

Now my question...How many and where are the cruise control sensors located.
I know the brake switch can act up and affects the cruise setting.
Possibly a sensor in the clutch system??
Are there any other switches and sensors that I should look at??

My uneducated WAG is the switch itself. If you press down and get the "Set" notification that then changes back to "On" smells like the down function is on the fritz.

I will guess the brake lights are staying on. Bad or dirty brake light switch. Not an uncommon problem for 2013 ST models. You need to get it fix soon. If you don't it can drain the battery while parked if you do not notice the lights still on. Personal experience here.

Had same problem just tap the brake peddle and then set cruise control it should work

Had similar problem, is a known problem with the brake peddle lever. Took it in and they replaced with a new designed lever, fixed the problem.

To all, Thanks for the responses.
I will be checking and cleaning the brake light switch
and brake linkage tomorrow.