The "HOT" and "TIP" target banks use seperate coils.
Do both banks reset up when you start a new game? (If so, the coils & drive transistors are working.)
Even if switch 37 (all targets down) is not registering, both banks should reset up on drain.
If the banks reset at start of game, but not on drain (and assuming rest of drain works... bonus collection, advance ball/player), then I would suspect a bad PIA maybe? Weird issue.
If it does turn out to be the actual mechanical drop contacts... I might suggest looking at these, instead of the ones you linked from Marco.
https://pinside.com/pinball/market/classifieds/ad/114469
I have not used them yet. (I have used the Siegecraft one's you linked, and they're fine.)