Zombie villagers that are converted back into regular villagers have the wrong tier 1 trades. When they unlock new trades, they are the correct trades for that villager's profession/career, but the tier 1 trades that they start with are incorrect.

Steps to Reproduce

1. Enter the following command: /summon minecraft:zombie_villager ~ ~ ~ {ConversionTime:1,Profession:0}. The zombie villager will immediately convert into a villager.

2. Right click on the villager to see its trades. (For some reason, sometimes when you enter the command, you can't trade with the villager. This may be another bug, and I might report it in another ticket later.)

3. You will see that the villager has the wrong tier 1 trades. Try trading with the villager, and it will generate the correct tier 2 trades.

4. Repeat step 1, replacing Profession:0 with any other number and you will see that the problem occurs with every villager type.

Notes:
Villagers summoned with the /summon minecraft:villager command have correct trades, but ones converted from zombies do not. Also, the tier 1 trades are from different professions every time.