The Bug:

When a villager has a low number of trades, the scroll bar is still present within the villager trading GUI despite it not being able to be dragged or interacted with; this is confusing.

Steps to Reproduce:

1. Summon a villager with a singular trade by using the command provided below.

   /summon minecraft:villager ~ ~ ~ {NoAI:1b,Offers:{Recipes:[{buy:{id:"minecraft:emerald",Count:1b},sell:{id:"minecraft:stone",Count:1b},maxUses:999}]}}

2. Interact with the villager to bring up the villager trading UI.
3. Take note of how there's a scroll bar present despite you not being able to use it.