Presets are part of the firmware, so you should consider a Factory Reset and/or a Firmware Revert. I can't say which one is needed to bring the presets back, but make sure that you have saved your own presets and projects/scenes on an external device (computer, tablet) before starting any reset procedure. Here are two article of Knowledge Base explaining the how-to:
https://support.presonus.com/hc/en-us/articles/115001731123-StudioLive-Series-III-Console-Factory-Reset
https://support.presonus.com/hc/en-us/articles/115004856203-StudioLive-Series-III-Rack-Factory-Reset-and-Firmware-Revert
I haven't seen any GEQ (graphic equalizer) presets anywhere. GEQs are used to correct/adjust frequency issues in a room and in monitors, which are always unique and always different. Therefore there is no real need for GEQ presets. If you think of PEQ (parametric equalizer) presets, there are only the presets from PreSonus in the firmware of all mixers. They are NOT needed to make a good sound. They are just examples and help to create own presets. You can also REDUCE and REMOVE settings of presets...