What I regard as a major security issue regarding cookies from a randomly generated identifier which immediately reappear as soon as I delete them

@DOW

Please edit your Original Post (“OP”) above, in order to remove the line:

<---------Delete this line and everything above before posting---------->

and everything ABOVE that line.

Your concern about “ghmbeldphafepmbegfdlkpapahbakde” . . . such a string of characters may be a Brave Browser Component or an extension ← that you may have added → In a Brave Browser New Window, go to: brave://extensions and see if some extension has that “ghmbeldphafepmbegfdlkpapahbakde” character string as its ID?

On your Mac, using the Finder, locate the “BraveSoftware” folder at: /Users/[username]/Library/Application Support/BraveSoftware ← Search therein (all levels of sub-folders), for a folder named “ghmbeldphafepmbegfdlkpapahbakde” ← it may be some obscure sub-folder, somewhere.

Brave Browser Components have similar names, and those components’ folder names, you will see in the “Brave-Browser” folder at: /Users/[username]/Library/Application Support/BraveSoftware/Brave-Browser/ Example: