recently I created a site collection with URL in lowercase. It was a mistake because it doesnt follow our URL naming guidelines. To fix this, first I decided to remove site collection and second, I removed it from recycle bin.
Then I created a new site collection with same title and URL but in pascal case. The result is that the URL still appears in lower case.
If I create a new site collection with different URL in pascal case, it does correctly, but with the older one this is not possible.
It seems that SharePoint Online caches the older name and reuses it when a site is created. Does anybody know a way to avoid this?