i got the squad editor from here:https://www.epicgames.com/store/en-US/product/squad/home and it does not appear on my library even though it says owned.
I also have this problem exactly as you describe. Did you find a solution?
I found a solution that worked for me. Since I don’t have any games purchased through Epic I had my Game Library disabled in the Epic Launcher settings. It turns out that Squad Editor goes to the Game Library not the Unreal Engine Library.
Go to Settings and deselect “Hide Game Library”
Then go to “Library” on the left panel and it should be there.