Are these both Smart Things Multipurpose V4? If so what's the difference?

I was given an old pile of sensors. I think these are all V4 but I'm not entirely sure. I've had a harder time pairing the version on the right and I've also got at least one of those which isn't reporting temperature and I wonder why (my HE C7 recognized it as a ST MS v4, which may or may not be correct; I dont know if HE discerns between v1, 2, 3, 4 and now, uh, 5?)

Thoughts welcome, thanks!

The one on the right is the 2016 version, which I think is v2.