villagers don't restock until all of their trades are locked out or a full day passes, and then when they eventually do restock some prices go up - happened with melons, pumpkins and glistering melons for me. not sure if it is intentional game design but it definitely seems bugged, if needed i can provide a video of this.
Duplicate of MC-167002. This is working as intended, and caused by the fix for MC-157136.