Claim Glitching and Stealing of my Beacon

Hello so I was just playing LKSMP and I tp 2 of these players LAPAYA and vhgaming and after that I played another game for a while and I went back to play LKSMP and I saw my beacon gone and I asked to of them and they said they had it and I they didn't have permission to take it from me. But last time like yesterday I claimed the beacon and didn't give them trust .But they were able to take the beacon and the beacon was inside of my claim.