@djsmiley2kStaysInside pretty strange. I would maybe capture upfront between the between isp1 box and your router to know if the data look like what. and the tech guy is good to ID thing ? just in case he didnt seen something ?

Turns out, 2nd ISP will happily route packets with the wrong source on em

everything else is 'normal' and no one bothered to ever setup the company as a ISP in the states, and we don't have any actual allocations lol