Both shift keys suddenly started acting weird

[prostakus]

I got myself a Dell Latitude E4310 and put in a brand new illuminated keyboard. After using the laptop itself for a month and the keyboard for a week the shift keys started doing something weird. I don't know how it happened. Sticky keys are turned off, I tested with Passmark and it seems like they work.

 

This is what happens while I hold the left shift with the same force:

 

asdAsdAsdasDsasdAsDAsdAsDaSDASDasDASdASDASdAsDasDASD

 

 

And the right one:

 

asDASdASDASdAsDasDASDAsdAsDaSDASDasasdAsdAsdasDsasdAsD

 

 

Now I have just switched the left alt to left shift for at least some convenience until I get it worked out.

Also if I switch the shift keys to something else they work just fine.