The bug

Using the arrow keys to increase or decrease the values of a slider will, every few times, skip some of the possible values. This can be seen in every slider in Chat Settings, alongside with the 'Sensitivity' slider in Controls (more generally, it affects sliders with a large range of possible values). The latter, for example, goes as follows for me: 100, 102, 103, 105, 106, 107, 109, 110, 111, 113, 114 and so on.

It's also worth pointing out that sliders with a smaller range of inputs don't actually skip values, but rather, stay on the same value for multiple key presses, which is the case for the FOV as well as the sound sliders. This indicates that pressing the arrow keys might be moving the slider a constant value for every slider, regardless of its level of gradation.

How to reproduce

1. Highlight a slider by pressing TAB a few times
2. Press the left or right arrow keys repeatedly, observing how its value changes
   → Once in a few key presses, some values will be skipped