You can utilize the item in the offhand while holding shears and looking at sheared snow golems or bogged

In version 1.16, a feature was introduced where it is no longer possible to use the item in the offhand when holding shears in the mainhand while looking at already sheared sheep to prevent you from accidentally using the item in your offhand when shearing multiple sheep. Relates to MC-126337. This change wasn't made to other shearable mobs. Possibly intentional. Even while holding shears, you can still employ the item in your offhand when looking at already sheared snow golems or bogged. This behavior extends to already sheared mooshrooms as well, which might be intentional, given that the cow resulting from shearing a mooshroom is a distinct type of mob.

Steps to reproduce

1. Hold a shield in your offhand
2. Hold shears in your mainhand

3. /summon minecraft:sheep ~ ~ ~ {NoAI:1b}

4. /summon minecraft:snow_golem ~ ~ ~ {NoAI:1b}

5. /summon minecraft:bogged ~ ~ ~ {NoAI:1b}

6. Right click all of the mobs twice

Observed outcome: When trying to shear already sheared snow golems or bogged, you engage your shield for defense.
Expected outcome: When attempting to shear already sheared snow golems or bogged, the offhand item should not be used, ensuring consistency with the behavior observed when attempting to shear already sheared sheep.