annotation disapear

Hello, So recently I just finished watching Boogie2988's recent video about how he got hacked and at the end of the video a thumbnail appears that you can click on and it works on mobile - an actual working mobile annotation I think! I couldn't believe it! Does anyone else know how to do...

I can't find this in forums or help. I've noticed my annotations keep disappearing when I add them to newly uploaded videos. This has been going on for the longest time and I can't figure out the problem. I noticed it happens when I add annotations to a fresh video I just uploaded. The...