Tartarus V2 - Keys Sticking/Repeating

I've been using a Tartarus V2 for several months, and so far I'm enjoying it. Feels great, looks nice, I'm pretty happy with it. Since I started using it, however, it has had an issue that I've been unable to fix through any means: every so often, a key will 'stick' and repeat its functionality after being pressed.

Here's how this problem manifests: As an example, I press button 8 (the W equivalent), to move forward, and when I let the key go, my character continues moving even with the button released. This "phantom" button press does not stop until I press and release the button again. (Again, this is just an example; it has occurred with every key I use for movement.)

Here are some other notes:

- I believe this is a problem with the software or firmware, and not a hardware one. The key mechanism is not dirty; it is not being mechanically activated. Experimentation with physically holding the key produces different symptoms than when the "phantom" keypresses are in effect.
- The issue happens once every few hundred button presses. If I'm playing a game, it occurs with one of my movement keys every couple of minutes. It's unpredictable and I am unable to intentionally replicate it, short of playing a game as normal for several minutes until it happens.
- This has happened in multiple games. Presumably it is software independent, with movement functions in games making the event most obvious.
- This has happened on multiple computers; as such, it seems tied to the Tartarus itself and not the computer it is attached to.
- Updating Synapse has yet to solve this issue. I have eagerly installed every update available in the hopes this would clear it up, but this has not solved the problem.

The closest thing I have found to others having the same problem are reports from several years ago of full Razer keyboards that ultimately were solved by firmware updates; between this and my own experience with the device, my suspicions lie with the firmware.

With no amount of physical adjustment or software changes solving this issue, what further options do I have?