Cured zombie villiagers' discount is not permanent

좀비 주민 치유 후 할인을 해주는데, 현실 시간으로 7일 정도 지나면 이 할인이 유의미하게 줄어듦

I cured several zombie villiagers so they gave me a discount. However, this discount did not exisit that long. The librarian asked 1 additional paper per 1 day in real time(ex:they asked 3 papers for 1 emerald,and the next day-in real time-they ask 4 papers for 1 emerald, and so on. On the 7th day, I could notice that the items became meaningfully expensive.). I have actually played mc about 10 hours a day...., can it be a reason? I am actually not sure if this is a bug or intended one, but I heard that in Java edition, the discount is permanent. Is it supposed to be the same in Bedrock edition too?