Not sure what to tell you, maybe try another wifi somewhere else. But if it was working and then you made changes to your router and it stopped working, I'd be reverting changes and trying again. Can you setup another router just for the tesla, maybe a spare.
Actually it works intermittently, if I turn on/off wifi it will for like 4-5 hours and afterwards it will stop loading. Very strange! Should I just try a random port to forward?