Running KSP 1.11.2; the TCS extends as soon as a vehicle is launched, whether to the runway or to the pad, and will not stay retracted. Clicking the 'retract' button causes the animation to show the TCS retracting, then it immediately extends again. This happens on even the simplest of vehicles, without any action groups implemented (see attached).

I tried putting a vehicle with TCS inside a fairing, then launched it and while it was on the pad I looked inside the fairing. The TCS' were stowed in the retracted position. But as soon as I deployed the fairing they extended.

There is a switch on the radiators called,auto deploy, have you tried to disable it?

In my case the switch is labeled "Automated" ... it was hidden in the action window by being inside the "Radiator" drop down section, and I somehow missed it. I tried it and it works as expected.

Thank you for taking the time to answer my question. My only suggestion would be that, since it's similar to a solar panel that it the default value be 'off' rather than 'on.'

I think I will intoduce a global setting which you can change to set the default behaviour