Have the same issue, whenever i change T to anything such as 3 or 5 it wont work, file is not in read only mode since when i change it, T also stops working.
Basically i have a big problem 3 is credit on my machine. Like the post i quoted switching to 3 wont work in that file.
Also tried an ahk, setting it to 1::send +t works fine, but if i do 3::1 or 3::send +t it will not work, the script itself works, i can test it in rocketlauncher, when i hit 3 it outputs a capital T. But for whatever reason, the game or its something on my end, will not allow me to map 3 as credit in anyway shape or form. Not sure if anyone can test this on there end, very odd. Not sure where to go from here. I just want 3 to be credit.