Tempo slider not working properly

Hey, I just bought a ddj flx4 and was everything working properly. But after my Rekordbox free trial expired (I dont know if it's relevant or not), the tempo slider of deck 2 is not working as it used to. When you slide down the tempo, instead of increasing, it decreases, but if you keep sliding more it returns to normal, the same thing happens when you want to reduce the bpm.

For example, in a 120 bpm music, when i start pushing the lever down, the bom goes down to 116 then it starts climbing again. I can play like this but more than half of the slider is unusable and beatmatching is a pain.

What should I do? beacause the deck 1 is working perfectly fine and I'm dont know if its a software problem or a problem in the controller itself. I think its important to tell that rekordbox does not recognize the controller when you plug in when its already open, it only recognizes when its already plugged in the notebook and then opening the program (it didnt happened before aswell).