After running /tick freeze, pausing, minimizing Minecraft, and then unpausing, the game will lag significantly before the pause screen disappears, sometimes to the point where it will freeze completely and say 'not responding'. This does not happen when leaving the game paused without minimizing, nor does it happen if ticks were not frozen.

Steps to reproduce:

Run /tick freeze, pause Minecraft, minimize the window, and wait a bit, maybe thirty seconds or so. Then fullscreen the window again and hit return to game.

Expected behavior:

There would be no lag, aside from the small amount that just exists because I'm on a laptop.

Observed behavior:

The game takes five or so seconds to respond, and will occasionally cause the cursor to become the loading wheel and the window will have (Not Responding) in the title. The game even crashed once. Don't have the crash report or anything for that since that was yesterday, before I actually tried to test this or thought about it too hard.

Notes:

I tried minimizing the game and leaving it for a while without having done /tick freeze first and it was just fine, same for leaving the game paused without minimizing. While the game was minimized, I was doing things in another window, mostly using GIMP to crop screenshots I'd just taken. I do feel like the game is slightly slower in general when ticks are frozen, but that's just my qualitative/subjective opinion on it, and my laptop was never all that fast anyway, so take that as you will.

Edit:

Here's a video I took. https://youtu.be/gc68mNXznAE. Apologies for the, uh, very high quality professional video you just saw, plus the fact that it's mostly just my desktop. It does only lag if you leave it for a bit though, it's fine if you just minimize and then fullscreen real fast. For the record, the low framerate once the pause menu disappeared was only the recording, it was perfectly fine for me. (And in the low-frame-rate bit I typed 'and now for comparison' and ran /tick unfreeze) The delay on the menu screen was accurately recorded both times, though. One more thing, it didn't lag after I minimized it right after starting the world, so that may affect it, but after I flew around aimlessly a bit and let all the chunks load, I got what you see here.