It might be that a scene you are using is corrupted. PreSonus recommends to always recall scene #1 ("zero out board") when creating a new scene. If you continue changing and storing "used" scenes, this will sooner or later cause problems.
Mostly the reason for "funny" things happening are too big steps between firmware upgrades. It also happens that an upgrade simply fails or does not update everything. The only way to "cure" the problems is a factory reset (with the option card pulled out). How to do a factory reset is described on this page: http://support.presonus.com/hc/en-us/articles/210047893-StudioLive-AI-Mixer-Firmware-Recovery-Factory-Reset. You can also find this document in your PreSonus account.
Please consider that a factory reset deletes ANY information (presets, scenes) stored on your mixer. You need to save them in UC Surface on your computer before you start the reset. You can also do a general "backup" in UC Surface, but this does not work with FireWire at the moment. You need to do the backup through ethernet.
