When attempting to cure a zombie villager which was previously a regular villager (ie not a naturally spawning or summoned zombie villager), and then logging out before the curing process is completed (~5 minutes), the zombie villager will revert back into a regular villager, as if they had never been converted into a zombie villager, or were in the curing process at all. This means any potions/arrows/golden apples used to cure these villagers will go to waste if the player logs out before the zombie villager has finished curing. Tested this on multiple worlds (1.18.2 windows 10 edition).

Here is a video demonstration of the bug: https://youtu.be/CyR520IoT1o