I will say that an intervening web proxy could also be returning the 403, which would be a difference between your environments.? If your IT people are sure there isn't anything there, though, then perhaps some combination of the user-agent and your source IP is triggering their DDOS/scraping protection.
Thanks Jeremy.
I suspected that as well, the Chromium build on these TPs are years old. Which in the Android world doesn't necessarily mean it's a problem, but that doesn't account for TB having it work in their environment.
