Same things happening with me in realms. The pumpkins were harvested in previous version. i tried placing the pumpkins and picking them back up to see if that would change anything but they still won't accept any of the pumpkins.
ok. sorry, first time on website.
(on Windows 10) Following Edward's advice, the pumkins now work for trading when placing/breaking them while facing north. dk why it works like this but its weird.