When switching game versions from 1.13 to 1.12.2 and similar, settings from 1.13.1 override other settings and often revert to defaults. My "Drop Item" key keeps reverting to Q, and Mouse Sensitivity keeping setting to 121%.

The settings appear to change when changing back to 1.12.2, or back up to 1.13.1,  reverting to defaults. Either settings are not saved per version or are being overridden somewhere.