Ouch, sorry to hear! Can you check the mapping you use for APOTU (in the steamvr controller settings)? It should be set for default, maybe theres a rogue custom mapping active?
You could try to also callibrate the thumbsticks (also in the steamvr settings).
I'm running it on Index myself, so it should work just fine. However, APOTU uses an old version of Unity's Input system, which isn't the greatest in combination with Index, I needed to apply some trickery to get it to work decently.