I’m not sure if DFX_NETWORK would make a difference, but possibly.
I think I found the problem, it’s because I was trying to login with the production Internet Identity canister. Apparently that breaks everything. Also running a separate vite server instead of deploying to the canister seemed to complicate things. I am at least unblocked.
It would be great if there were a simpler solution for running a frontend server that doesn’t require much extra configuration or proxy settings, but for now I’ve moved on from that. II was messing things up so much I’m not even sure if my previous assumptions or observations were correct.