This only happens on the USB drive, as far i can see; all other relative sizes are shown correctly. When i look into a subfolder, consisting of folders based on various dates, some folders show wrong sizes.
Here is a screenshot of the folder after it has been opened:
when moving the cursor down (per keyboard), the correct sizes will be revealed, after the focus striked over the folders:
Does it have automatic folder size calculation turned on?
BTW, what does the relative size column title translate into? Datentrager looks like "date range" which shouldn't be in the relatives size column's header. Maybe that isn't what the word means though. 
I am just guessing based on the English words that it looks like.
[quote="leo"]Does it have automatic folder size calculation turned on?
BTW, what does the relative size column title translate into? Datentrager looks like "date range" which shouldn't be in the relatives size column's header. Maybe that isn't what the word means though. I am just guessing based on the English words that it looks like.[/quote]
Well, "Datenträger" means about "data carrier", & now that you´ve said that, the problem is solved.
I didn´t mean to use "relative size on medium"¹, but only "relative size", & after i changed that, it now shows the correct values. But you can still see a glimpse of the "relative size on medium" bars for a split second when the window is drawn. It looks like on USB drives the previously used spaces possibly are not freed up in terms of displaying the currently used space. That would be an explanation. Thank you!
¹ Sorry if this is not the precise translation for the item, sometime i must translate all the english terms of the menues & prefs into a reference table.
Relative Größe auf Datenträger = Relative Size on Disk
yep, thanks/Danke!