I do too. But I think you are taking about the schrader valve or valve stem core. Yes they come loose. I also have had them stick open on those win lite front wheels. Added some air. Go to the other side of the car and do the same. Come back over to the first side to put the cap back on, tire is FLAT! Valve core was tight, just stuck open. I have had good luck with those by squirting a little WD40 and then add some air right after. Never stuck again after that.
In my post above I am talking about the TPMS NUT Coming loose. The external aluminum nut on the TPMS Valve Stem.
Mine didn't necessarily "come loose", it was tight and was checked to the bottom end of the tq spec. Consequently, it was ruled as not being the issue (and by Michelin Engineering that helped me troubleshoot the issue at my garage).
It was only when we really started to go crazy and were double/triple/quadruple checking things that one of the guys from Michelin very firmly pressed against the TPMS stem (simulating centripetal force from very high speed) that we got it to leak.
Re-torqued everything to the very top of the TPMS nut tq spec and magically we were no longer able to cause a leak, and confirmed it with a ~180mph run (unofficial).
Another thing I did was to replace the o-rings and very carefully debur the hole the next time I dismounted the tires, but I did this after we had already solved the issue.
A deeper dive into why I didn't initially use the high end of the tq spec is that, one, it's not normally considered good practice when given a tq range, and frankly, when you do use that spec, it really doesn't feel right, that nut doesn't give good feedback when tq'ing that much, but I think some of that is the rubber interface on the stem.
.02