I made a home ages ago, probably over a year back. No updates have broken it, and I can teleport to it just fine - I have three different teleport "bookmarks" there, and they each work. I recently started playing again and learned that you can make space stations.
I wanted to put one in orbit above the existing base, so I went about trying to find it. Obviously just fumbling around the map looking for the name was out of the question, and there's no way to search for it by name. So I tried two other methods:
First, I cracked open the universe folder and looked at the filenames of recently visited planets. I'm sure I was doing this somewhat wrong, since some of those co-ordinates didn't even go to systems. I tried different permutations on negative and positive co-ordinates, and still couldn't find the system - although I did visit a few of the ones I checked.
Second, I obtained a quest on the planet. Looking at the GUI for the starmap, I noticed you could move to whatever your active quest location was. So I plopped down a couple colony deeds, did a lap around the world looking for active NPCs to no avail, went downstairs and accepted a quest to kill a dark knight in the abandoned cabin next door. However, when I went back to my ship excited to have a bookmark, it wasn't there. The fact that the automatic planet-marking that the quests do has me concerned that this planet plain isn't reachable by space.
As a followup, I beamed down to a nearby planet, got a quest, and verified that the quest tracker did work for quests I accepted... today.
The tl;dr is - is it possible that an update or error removed my planet from the universe, but not from existence, allowing me to reach it by bookmark but not by spaceship?