When I export sheets from Revit, different sheets overwrite each other.
Sheets that overwrite each other have identical GUIDs. This usually happens when you create several sheets from a template, as all of them inherit the template’s GUID. To view a sheet’s GUID, open the sheet properties in Revizto and find the "Internal ID" value.
Your export settings define that Revizto maps sheets by GUID only. It treats sheets with identical GUIDs as versions of a single sheet.
To correct the problem:
In Revizto, delete all sheets that overwrite each other.
In the export settings, clear the Merge similar sheets from different files checkbox.
This adds the comparison of .rvt file names to the sheet mapping rules. Revizto will treat sheets with identical GUIDs that are stored in different files as different sheets.
Re-export the sheets.
For correct export of future sheet versions, ensure that the Merge similar sheets from different files checkbox is always cleared and the .rvt file names never change.