I have old 1.15 villagers with old trades, such as farmers asking 16 eggs for one emerald. These are villagers obtained before the parity update that matches Bedrock trades to Java trades. Some of their trades, such as the egg one, are completely unaffected by zombie discounts. Other old villagers like my toolsmith have this issue as well, some of the trades are completely unaffected by any discount mechanics. Newer villagers that I obtained are working as intended.

Note that I haven't traded with them for a long time, so the supply & demand mechanic shouldn't take effect. They are also using beds and job sites to restock.