Free Lead Glitch When Close to Wandering Trader?

I was standing close to - but not directly next to a Wandering Trader when I left my survival world. I returned to the home screen, then reopened the same world after a couple of minutes. Upon reentry I found that the item I last had in Item Slot 6 had been shifted to another square in my inventory and my on-hand item was a now a Lead - I did not have any leads in my inventory prior and I had not come into contact with or made one on that world yet. I suspect it has to do with the Wandering Trader and his Leads for his multiple Llamas (This Trader has 2 Llamas), The Wandering Trader is operating fine and so are his Llamas that still have leads. Basically I just gained a lead - thats all that happened. I was about 1-3 blocks away from the Wandering Trader when it happened - there was a 1 block high wall between us. I traded with him once about 30 minutes prior. I hope this is enough info but happy to ask any questions