I use TouchDesigner also. will check in a couple of days.
It's most likely a connection issue, but if it's only weird with the keyboard In CHOP (sorry for touchDesigner jargon. Just trying to see if it's a Twiddler , Bluetooth connection, or TouchDesigner issue) but fine when typing into a normal text field. try enabling 'force cook' to make sure the Keyboard In CHOP is listening on every frame, I forget if you can do that in the CHOP itself. You might need to append a Null after it and tell that to cook every frame - that will force the ones upstream from it to cook as well.
Have you tried another bluetooth keyboard yet? It may be affected by where the bluetooth receiver is on your computer. If it's a desktop, I'd suggest getting a USB extension cable to locate the Bluetooth dongle more in line-of-sight to the twiddler (assuming that your twiddler works fine with a usb connection instead of wireless).