I have confirmed this and am writing up a ticket/doing a bit more digging into this. One more question @bdubyah if you don't mind, does this happen to other blocks than a vending machine? I suspect not, I believe it's a case of SecureLoot not playing well with the vending machines (technically being traders), over networking and this doesn't happen to other blocks with SecureLoot, but I just wanted to be sure 
Note, I don't mean for you to go checking a bunch of blocks, I can do that, just if yall have seen it being thrown with other modded blocks with SecureLoot ^^