I placed a villager and a work station (composter). In a well lit, secluded area. I went about 100 blocks away, and I returned to find the composter, and the villager had disappeared. This has happened twice within a 15-hour timespan now. I am on a realms server, but I have been the only individual on within this time span. I am running Optifine version 1.16.4.
I have included a before and after of this, including a timestamp in the bottom right corner.
This report is a duplicate of MC-193509, which was later marked as invalid, because this issue is caused by OptiFine. See the parent ticket for further details.