check for slide wear on the mounts
if it has any it allows the motor and saw to drop sideways and alter the cut angle
you can compensate by moving the setting that bit extra and the locking it up
The brake on your mitersaw is an electric brake. When you release the power switch, the switch sends current to a brake coil in the motor's field. This reverses polarity to the motor and stops the armature from spinning. Good contact from the motor brushes is also important for this to work correctly.
The most common issues with a mitersaw brake are the brushes, part number,CB-154 , and the switch part number, 650618-3. It is less common but a damaged field can also make the brake not work correctly. It is part number 596356-2. https://www.ereplacementparts.com/makita-ls1216l-1234-dual-slide-compound-miter-saw-parts-c-97_98_99_40150.html
Sounds like you have a broken spring, which you may not be able to see.
Type "Makita chop saw" into the search engine of your computer, and a list of dealers should come up for you to call and ask your question of.
God bless your efforts.
the cutter roll/blade is not parallel to the cutting deck so one end needs adjustment
it could be from the cutters being blunt at one end and that will produce extra pressure at the other end or is not cutting as efficiently as the other end resulting in the problem
It's possible that the blade is not seating or seated properly, the guide is bent or out of alignment, or an incorrect blade length is being used. See my request for information, and supply an image.
