Eerie Mojang office server event is crashing randomly

So when I was joining the minecraft server event, I came across that my game crashed all the time and I restarted my game and it didn't work, I want that cape and I only completed 2 challenges and it crashed but I don't understand why It crashed, maybe because I have lag or it just happens randomly but can you fix this bug in 1.21.52??? It still crashes and I want that cape

Sincerely

Dylangamez9817