Controller Issues after Repair

I repaired a JDM 30 controller by soldering a new right stick onto it, I have two issues now that maybe someone has an idea how to fix.

First issue: the right stick now does a rectangular motion instead of a circular motion if you use it and do a 360 degree rotation.

Second issue: After putting the controller back together, when I press firmly so the two controller shell pieces are pushed together, it will disconnect for a second and then reconnect (using a usb cable). I’m not sure if the reset button gets pressed then, but I doubt it is because everything is back together the way it is supposed to (but maybe apparently not?)

Any help would be appreciated, am going to use the controller on pc and ps4 again.

Can only help with 2nd issue:
The charge cable from the port to mobo. Either the band is gone bad, or you haven’t quite put it back in correctly. I would try a new band, and careful with bending, if needed.