I have scanned old map (no grid ref etc) and then assembled high res JPEG in Photoshop (but obviously could save in other file format, e.g., TIFF) I am now trying to georeference in QGIS 3 but on trying import raster I only have weird coloured box in middle of Georeferencer (where my map) should be. I can open other JPEGs (not photoshopped) but don’t understand what doing wrong. Is there something embedded in PS JPEGs that QGIS doesn’t like. Do I have to run through image converter? If so, what? I am running on a Mac.