I have recently downloaded the 3.28.9 version of QGIS and I am having repeated issues of shapefiles disappearing and parts of shapefiles not selecting when pressed. The shapefile disappears when zooming in and the virtual area field in the attribute table becomes a random negative value.
To fix this I have ran the shapefile through multipart to single part, and then fix geometries. I then have to overwrite the current shapefile as copying and pasting the new polygon doesn't work either. This seems to work with the feature but once I edit the polygon it reverts back to this state.
It has only started happening since this updated QGIS download which makes me think it is a version issue rather than repeated broken geometries. If anyone else has had this issue, please let me know how I can resolve it as it keeps happening.