QGIS » QGIS Application

So it seems like to me that it's just the initial state of the EPSG display in the status bar which is wrong. It's showing 4326, but the project is actually in 3857. You can confirm this by opening project properties and checking the CRS - the status bar should switch back to correctly show 3857.

Can you confirm?

You can confirm this by opening project properties and checking the CRS - the status bar should switch back to correctly show 3857.

The status bar doesn't update to 3857 here when I'm checking in the project properties.
What do you do to update the status bar ?

Just open project properties and flip to the projection tab

Ah yes, it updates the status bar and in pyqgis too.
Will you fix the initial EPSG state ?

It's not on my personal list of stuff to fix. Maybe someone else will volunteer to look at this one.

I'm fairly new to bughunting, so excuse me if it is a red herring and/or wrong code.
https://github.com/qgis/QGIS/blob/master/src/gui/layertree/qgslayertreemapcanvasbridge.cpp#L146

it checks, at loading of first layers, if the layer's crs has changed. It just checks for it is vector data and if those are valid.
Including something like (see below) may resolve the issue.

        QgsRasterLayer *rl = qobject_cast<QgsRasterLayer *>( layerNode->layer()

        if ( rl ) 
        { 
          mCanvas->setDestinationCrs( rl->crs() );
          mCanvas->setMapUnits( rl->crs().mapUnits() );
          break;  
        }