V2.86 is the latest version - there are no further updates.
However, you V2.21 is an older version and my information suggests that updating to ANY versions of firmware above this may cause issues with the system, including resetting the unit back to default values. If you are going to update it, then I suggest you follow the Mirascripts Part A and later Part B, from this guide which was written for replacing the internal MicroSD card when it fails. Using the Mirascripts programme to copy over your system configurations file, will allow you to restore your user data files back after the firmware upgrade, which should hopefully restore everything to normal.
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