I had this Iron Farm in my spawn chunks because I want it loaded all the time because I am starting a big project for my new world. But the Iron Farm wasn't working at the spawn chunks. I put it there so it would work always even though I am away(Away as in the overworld only). So I had this problem as well on my old world but I didn't really bother because it was an old world and the only way I looked for my spawn chunks was only from my compass but the new world (The one that has a screenshot) is new and when I generated that world I immediately took a screenshot of the spawn chunks. No, Iron farm is not outside the chunk.
The 1st picture was when I first loaded it and it was the chunks where I spawned I never moved (Optifine)
The 2nd picture is the exact spot but in Vanilla 1.16.3
The 3rd picture is showing that the iron farm is indeed inside the spawn chunks
Please correct me if I am wrong.