Reduced prices from cured zombie villager dissapear after re-loging in on realms

I cured a zombie villager on my realm world yesterday.

When I logged back in today the price reductions were gone, at least visually. I haven't tried actually trading yet.

Possible causes could be:

• me logging out

• a time out

• an IOException

(Sorry I don't remember the exact way the two last ones were phrased)

These are the three only events that happened since yesterday.