Minecraft launch settings are not saved

Minecraft requires 2 GB of RAM, which is exactly the amount indicated in the launch settings. This value can be changed to your liking. For example, I set from 4 to 6 GB of RAM to make minecraft work better and faster. But for some reason, the launcher does not save this value and discards all changes. Therefore, I always have to change the value to my own, every time. What is the reason for the reset?