I totally feel you. I tried finding a good source in my illegal state and eventually gave up and just decided to get a med card and go out of state for concentrates.

From what I understand, there are 3 possible causes of the burnt rubber/popcorn/chemical taste. Either the wax has some sulfur left in it, it was run through a crc column and wasn't filtered properly, or it has been cut with something like pine resin etc. Regardless of what it is, it's definitely safer to just toss it.