I just tried it again with a fresh account using chrome here on PC and no issues at all.
When hivesigner send you back to my site with an "OK good guy here" token, I consume it in a script and then push you to the profile settings dashboard logged in. So you will only see that long token url flash up for a moment on the way back before redirecting to a logged in page.
Unable to reproduce, feel like that denied login and safari and then chrome got your auth and link caches mixed up, but im not sure, thats just my gut at the moment, a clean browser cache and clean hivesigner account and it should be fine.