I noticed this in several games where you need to keep ‘e’ pressed to do something, like carrying a cube in Portal 2. The key registers for an instant but then it’s like I only tapped it even though I’m still pressing it.
Can’t replicate this here. Neither in Portal 2 nor in a brief debug session which did not show anything unusual. Keys are pressed as long as the according Touch button is pressed. Since there also have been no other reports of such an issue since Touch support was added almost two years ago, I have to assume that it’s somehow system specific.
If you have any additional software running in the background that might send Windows key events (e.g. Pinnacle Profiler, XPadder or similar gamepad tools) or that otherwise seems related to configuring/altering your keyboard please disable them.
As a potential solution you could try to switch the Touch controllers to gamepad emulation mode in vorpX.
If anyone else experiences this issue, please let me know.
The issue resolved itself in Portal 2 (and I noticed it had toggle, not hold, for picking up cubes). In the other game I encountered the problem, switching control back from gamepad to keyboard/mouse helped fix the problem.