Refer to the picture, normally drives X: and Y: are used for other connected external drives which will show same icons as the other two.
During when they were not mounted, I connected external cloud drives with RaiDrive (X: and Y:), which typically show that icon. However, after disconnecting external cloud drives and re-connecting my usual external drives, the icons are kept as shown.
I think probably some registries about the icons need to be deleted once disconnecting cloud drives with RaiDrive. Just a guess.
Kindly check. Thank you.