I am using Mageia 8 KDE.
I have just tried to delete the Wastebin after being informed that it was full. Delete wouldn't work on one file so I resorted to using the Konsole as Root. Eventually I cleared everything, but it seems necessary for the developers to smarten up the behaviour between Dolphin and the Wastebin.
In the /.local/share/Trash/files folder were listed "ancient" folders not displayed in Dolphin. And Dolphin's View/Refresh was erratic.
Another observation (going back several Mageias) is the apparent "jumping the gun" behaviour of the Copying window in Dolphin. The display seems to inform that copying is finished when the flashdrive is still flashing. Is it Dolphin "j.t.g." or the USB stick lagging?
Cheers (nothing else to whinge about!)