Iron golem (along with lead) despawned?

I was playing on java edition, and i afkd within about 20 feet of my iron golem who was attached on a lead to my house, and i was secluded in a second house. i was gone for probably about an hour, as phantoms were appearing, but when i got back the golem was gone. The lead rope tied around the fence was still attached to the fence, so i saved and quit and re opened my game but the lead just vanished entirely at that point. It took almost all of my iron as im kinda poor atm in my current save file, so im kinda dissapointed that this happened.