So.. this is kinda like a glitch too. I took a break from playing Minecraft for a bit. I come back and found that my island level is 0 and I am the owner, but not. When I do /is which should take me to my island, but instead takes me to the "start a new island menu". Also my island members DinoRider and _UrGrampa aren't able to do the same. They can't do /is. I am able to break blocks, open chests, and I also still the island leader.
From the screenshot you provided, try doing /is level /is should work though If that was your island in the screenshot, how did you get there? DM me your answer on Discord General_Grapes#4522