to reproduce:
1. wield an edible food in offhand slot.
2. have an item selected in hotbar for example iron ingot.
3. make sure you have full hunger bar and hold right click.
it thinks u have food in right hand and tries to start eating iron ingot
(does the same thing with empty offhand and a food item in right hand and full hunger bar), screenshot inluded also, I tried looking for a report regarding this issue but didn't find one, sorry if this was already reported.