The overwhelming majority of clickable items, such as quest clues, do not properly display when I’m playing. I click on them and the HUD interactive mode screen pops up for anywhere from a fraction of a second to several seconds, but automatically closes without displaying the clue image. While I can technically get around this by googling or hitting the wiki for the clue, it really takes me out of the game experience and isn’t very fun. Hope there is a fix for this if it is a known issue.
I have not heard of this type of behavior, so I can’t point towards any “known” solutions.
If you recently started playing or reinstalled the game, slow loading can be a side effect of ongoing background downloads (indicated by a spinning icon in your topbar). That can be mitigated somewhat by checking the “full client” download on the patcher and uncapping its background download speed.
If you see that icon in-game, it’s best to stay put and let the download finish before proceeding. Note that background downloads will periodically happen on-demand even with the “full” client checked.
FYI: Most image-based clues can also be found in your quest journal (J by default).