The only thing I can think of that explains this behaviour is that the fix went wrong somehow. If that’s the case, I don’t blame you, it’s quite a difficult mod.
In any case, I think the best solution is for me to just send you a new board (from the set of modified v3.3). Then we can check if the problem persists.
Please email oskar.weigl@odriverobotics.com with your name and address.
Ok, I will be in touch. In the mean time I will use the existing board and an arduino to give UART a go.