引用自 tojake2：

When you level up in a mech, you don't get the level up notification, and I think it messed with my skill stats so I had to reset them, and luckily had all of my skill points available to use.

This is a known bug that is already fixed on Github, but not pushed to Steam. Because of the way Skill Points work, however, you will always be able to use the Reset button in the Skill Tab to receive all of your Skill Points back, which is not lucky as much as it is purposeful :p