Global Captive Breeders

CB...in Indonesia? Unless Mitch can show otherwise, that to me says that they were bred by "wild" adults living in a huge caged in colony under wild conditions (except for the cage) and people go find the eggs or hatchlings and ship them here. They have ALL the same problems as wild caught, because they live in the exact same conditions.

So in the future, treat anything with that sort of label as though it were WC and have it dewormed.

As far as the ticks, it is possible that they came from you. You mention you use mulch, and I am sure some sort of cage furniture as well. When purchasing that stuff you could check out where it came from and treat it for possible parasites that are from that area. And be aware some parasite eggs are really hard to kill.
I am not saying one way or the other, I would lean on them coming in with the animals myself, but you should be aware of this for future reference. Baking will not kill everything everytime.

At any rate 4 ticks would not be enough to kill an adult monitor, unless they transferred some disease to it. Most likely it was internal parasites.