Game freezes for a second when opening the trading UI

Summary:
Opening the trading UI causes the game to freeze for a second. This bug is similar to MCPE-41772, however, you do not need enchanted items or shulker boxes for the lag to show. It lags even if your inventory is completely empty. 

Steps to Reproduce:

1. Spawn or find a villager

2. Open its trading UI

Observed Results:
The game freezes for a second.

Expected Results:
The game should not freeze.

Video:

Notes:
This issue seems to be more noticeable on lower end devices.