following the update on 11/18 my gaurdian farm stopped producing xp

I was playing the other day and crashed when I believe the servers refreshed for a sec to do a snapshot update or something. Following that my guardian farm has stopped producing xp. The guardians still spawn inside the kill chambers and are killed by a piston trident mechanism with the loot brought up to a collection system still. however no xp orbs are produced upon the guardians death. and the area is extremely laggy when normally the area experiences very little lag. Other areas of the realm are functioning just fine. Thanks in advance for your time