Minecraft becomes so laggy sometimes that it nearly becomes unplayable in 1.16 beta, I have the lowest possible settings and the game is still very laggy in Nether and in Overworld, this happens very frequently and relogin6g most likely won't fix the issue, the game becomes really unplayable when flying in creative or with Elytra, so it is a chunk loading issue, it seems this issue is caused by massive builds, maybe because I have a massive world but it even occured in a new world in the Nether and the End too!