What is this wart on my Lavender Orp's beak?

[nuthatch]

 

[Eggcessive]

This type of lesion is very common. There are dozens of posts here with identical pictures. But no one seems to figure out the cause. Many times it disappears after awhile. While some seem to think it is a virus, most seem to thinkit may be some irritation from rubbing against a waterer, feeder, or sharp fencing. You might go around and check for anything in the area that could cause this. Here are a couple of similar lookking bumps:
https://www.backyardchickens.com/t/494097/wart-like-growth-on-beak
https://www.backyardchickens.com/t/407306/please-look-3-chicks-w-growth-above-beak