I have a layer of ZCTA features that is sourced from a SpatiaLite table that is joined to an Excel spreadsheet and rendered with categorized symbology. That all works fine. The join configuration is:
I have found that after I edit the spreadsheet (using the column that the categorized renderer uses), I can turn the layer off, and then turn it on again. And the layer will refresh and change color. But only once. Subsequent updates to the spreadsheet do not trigger any changes in the QGIS Layer.
I am setting up this project for a non-GIS user, so I'm hoping to avoid any PyQGIS as presented in these answers: Make a Qgis layer update from a changed data source
Does this capability exist in QGIS 3? Something like an "Update All Data Sources" for a selected layer?