Topic: Weird Wii U Pro Controller stick desynchronization

Today, I was playing Super Smash Bros Wii U with a pro controller, and when I was scrolling through the character selection screen, I noticed that the stick movement would get weird if I played around with it. For example, if I move from left to right, then make circles and turn left again, the hand would move diagonally to the right (This is done quick). I was confused as I had never had this problem before. It got weirder because two pro controllers were connected at that time and we both experienced the same problem (It also made me drop from the ledge during a fight ). The gamepad and the classic controller didn't seem to have this issue. I went to the Wii U home screen and it still happened with both pro's. I then proceded to restart the console (OFF>ON).

NOTE: the second time the console was turned on was through the quick start menu and smash wii u was loaded immediately, however, I can't remember if the first time it had also been with the quick start menu.

So, it was on again and the same thing happened in both the menu and smash character select screen (obviously during matches too). I didn't try playing too much as I had to leave my house. When I came back I turned the console on (no quickstart menu this time) and everything seemed to be fine. I toggled the stick as crazily as possible but it never did any weird things.

I don't know if it's just me, but I've had some issues with the quickstart menu. Before, if I tried to access an application with internet capabilities through quickstart I would get connection errors (ex: smash online if software booted from quickstart, also eshop). However, I haven't had any of those lately.

Is it possible that QuickStart menu is striking again?

I've tried a couple of times to check the controlers' behavior and everything seems fine. It could also be a one time thing (or two time thing, actually).
I still haven't tested with the QuickStart menu again to see if the problem happens again, but I'll update as soon as I can.

I just want to hear any opinions, experiences or possible solutions (if any).
Thanks for reading this!

I don't know the synchronisation technique built in the WiiU controller but the GameCube- and Wii-Controllers have an easy synchronisation technique: When they get power, the current position of the control stick is saved as the neutral position.
Maybe you touched the control sticks while starting game via quick start!?

I did take care of this when turning the console on for the second time. Also, if it had been that, the problem would be extremely consistent (like not letting me move at all) rather than happening only when moving the stick around a lot.

UPDATE: Happened again without quickstart menu. Seems to also have happened with classic controller.
Just to clear this out, I was using a game filter on my monitor screen to play but I honestly don't think that is the problem. However, this has only happened during the game mode of the monitor screen and I'm checking if it happens without it.
To clarify, the problem is also shown in the gamepad, and that is the reason why I don't think it's the filter.

Happened without the filter, and I don't know what to do. Removed the internet modem that was right in front of the console in case it was causing any signal interference.