Please complete the following.
Factory Reset - Home Key - Reverts mixer back to its base firmware. Link: https://support.presonus.com/hc/en-us/articles/115002810486-StudioLive-Series-III-Console-Reverting-to-the-Factory-Firmware-Image
Then,
Re-update the mixer to firmware v2.3.16845 using the SD card method, when confirmed do the following,
Factory Reset - FX Key - Wipes all user data from the mixer. Link: https://support.presonus.com/hc/en-us/articles/115001731123-StudioLive-Series-III-Console-Factory-Reset