This could indeed be an explanation, especially since the SDL2 library under Linux is regularly updated to implement new game controllers support: it could explain that the issue is showing off now, and not in other Linux viewers using older SDL2 versions.
The last time SDL2 was updated was
in June, in v1.32.0.25 and v1.32.1.8...
Also, some game controllers might start (when plugged or when the PC is started) in digital mode, while the viewer uses them in analog mode, which could also explain the bouncing until they are toggled in the proper mode (there's often a button to press on the gamepad to do so)...
An update to libinput on the Linux system might also be the cause of a sudden gamepad glitch... Arch Linux got a good
Wiki page about game controllers configuration.