Nether portal despawns items glitch

Hello, I recently discovered a bug on my survival world involving the Nether. When I went through the portal, there was a vindicator waiting on the other side and it killed me whilst I was still inside the nether portal loading into the nether. I respawned and went back to the nether and killed him. I then notice that all my items were gone. It was in a enclosed space and all of my loot was mainly in the nether portal when I died. I think what happened was the nether portal teleported my stuff thus making it despawn somehow. It only took me a measly minute or two to kill the vindicator and to realize all my items were gone. Items don’t despawn in a minute or two naturally and I also notice when I died I saw my items being teleported in the nether portal. I never saw them again and I had some really good stuff too. Please fix this bug.