Realms (429): Unfixable error???

I have played realms before, with no errors.  I closed out of mc, rejoined, and was greeted with Realms (429):   Not sure what is wrong, and i haven't gotten this error before.  Some of my friends have gotten this error too, and we can't play anymore.  I think Mojang needs a client update, as a 429 error is when too many actions are taken on by the client, but not sure.  I loaded 1.16.4, then loaded optifine 1.16.4 again, and it sometimes work, but I still get the error