DisplayLink Manager Keeps Reinstalling Itself...

You can check to see if you've removed all of the supporting files by downloading and running the shareware app Find Any File to search for any files with the application's or the developer's name in the file name.  For DisplayLink Manager software you'd do the following search(es): 

1 - Name contains display link

Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.

➙ FAF can search areas that Spotlight can't like invisible folders, system folders and packages.

If you get warnings that the file can't be deleted because it is in use or used by another app boot into Safe Mode according to How to use safe mode on your Mac and delete from there.

Note:  if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode.  This makes it act as a wired keyboard as will assure a successful boot into Safe Mode.

Good to hear it worked :)

If it keeps reinstalling itself, you could take a look, if there are Display Link related startup items, which you should/can remove.

Open System Settings > General > Login Items and review the content there. There might be something you can remove or at least disable.

Hi,

you could try using this free tool: https://freemacsoft.net/appcleaner/

Often it find's relates files and you can delete those as well with it.