The Neds glitch out sometimes if you destroy certain things in his shelter before you try interacting with him. Once he is glitched there is nothing you can do to fix it.
As for the DBNO survivor, you can’t interact with him because husks were attacking him at some point and moved him from his original spot. You can still interact and request the medbot but you will just have to search around the immediate area to try and find where the survivor originally was. That is where the interact box will pop up.
These bugs have been in the game forever and will never be fixed because it is Epic.
Thanks for listing out possible leads to this bug. Being able to reproduce this issue will be a big step forward for our dev teams, and help them solve this bug sooner!