Tbh, my collection is very small anyway and I’m sure most were recognized before. If manual is preferred, then I will continue this way. At times, there have been issues with the server pulling the boxart down, so maybe this is the issue but I’m going to start by clearing my thumbnails folder and rescan (manual) and see what happens.
EDIT: Thinking about it, would placing in multiple sub folders affect the scanning, as previously all the roms were at the same level (ie. arcade) whereas now they are in the manufacturer, hardware folders (ie. sega, system 16).