I've just upgraded my survival world to a 10 player Realms plus world, and I've just logged in after the first payment went through and my game is lagging

I bought Realms plus and converted my survival world into a 10 player realm server and I've just logged in after the first payment has gone through and my world is lagging. I've noticed that it sometimes takes a few seconds to open my inventory after pressing the inventory button, when it's usually instant. I'm also having trouble firing arrows from my infinity bow; sometimes it takes a few seconds to fire, or sometimes it doesn't fire at all. There are also obvious lag spikes where mobs stand still and then jump to where they should be as the game catches up.

There's lots of little lag problems like that happening now that my world has been fully updated to a realm. I don't know if the server needs time to catch up, or if this is actually a bug.