Sandbo Chang

I should also add that it happens even though now I turned off VSync for the game. Whenever it changes from midnight to day or day to night, all lava or candle lights will be gone and framerate dropped to single digit, which is otherwise 45+ on my 3070.

Yes it’s still happening in 1.20.1

Just want to add that if the solution is to modify the game config files, one can use the unofficial launcher for bedrock and you will be free to modify anything. The game runs exactly like official launcher would and that’s what I have switched to when testing different version of dlss file.

Pretty sure this problem is associated with DLSS.
If you delete (doing so you will need to reinstall the game) nvngx_dlss.dll from the game engine's folder, loading a RTX texture-loaded game will work 100% of the time.
Certainly then this isn't a solution for most people I guess.

I tried also changing DLSS version by using the custom loader, the result is still kind of mixed for me.
This crash probably didn't happen back in 1.16/1.17, not sure if it came after 1.18 or 1.19.

Update:
I found that nvg_dlss.dll of version 2.2.6 seems to work best so far, tested and it worked 4/4 times success. I was thrilled.
Going back to the latest 2.4.12_v2, instantly failing again, worked 0/2.
Finally, moving back to 2.2.6, I got 1/2 times working.
This may not be an actual solution, but if you are seeing 100% failure rate, give it a go.

To try a different dlss version:
1. Download Custom Minecraft Bedrock Loader
2. Download the desired version of nvng_dlss.dll from Techpowerup website.
3. Open the game folder, go to C:\Users%username%\AppData\Roaming\.minecraft_bedrock\versions%game-version%
4. paste and replace the nvngx_dlss.dll file inside the folder

@JohnnyTamale1, You are right, for a while I thought it was the cause of the RTX problems. Turns out it's more general than that unfortunately.

And here is now a video showing exactly what it looks like in the case of RTX texture packs.
It's basically completely broken.

https://www.youtube.com/watch?v=7-PU41xuLPo&ab_channel=silentwisperer

Just looking this issue up as I had the exact same problem.
Was fine with 1.19.11 or earlier RTX resource packs.

Haven't seen this issue before, but now it shows up for me too on 1.19.20

This isn't fixed in the latest update today, which is really ridiculous.

It is still here with 1.19.

It is now again here with 1.19.

Note: I almost always play in single player mode. When you play in MP mode the client and server have to talk to each other frequently so the server can detect it if the client disconnects.

That is it. It appears to me as a design flaw inherited from making it work cross platform where minimizing the app tends to put thing in pause and server disconnect the client.
Clearly this should not have been the case when connecting from a PC client, and the Java version never had this issue. And I don't understand how the game can't use the network if it is minimized; other Windows app did not show the same behaviour.

Alt-tabbing is a very routine part of even gaming on a PC, like replying to a message, the server is basically cutting off connecting in a second or 2. Maybe a solution is to make the drop takes longer to happen?

@Auldrick

Mind providing details of your system and maybe setting for minecraft bedrock?
In my case, it makes no difference and the disconnection is almost instant, like any minecraft version before.

As it drops to 30 fps, I was guessing it was caused by a bug related to VSync, and it seems to be the case.

With Nvidia card, I force disabled VSync in the control panel (can also be done with AMD), instead I limited the refresh rate to within the monitor's Adaptive sync range. 
After that I have yet to experience the framerate dip.

If I am kicked by the bug,  relogging to the server will show everything but torches in perfect dark. This is with 1.16.210.06 and ray-tracing on (likely the cause).

Example here

Now it means alt-tabbing out of the game, even for just 1 sec, I will have to restart the game.

Having the exact same issue as described. Funny thing was, I was fine with AMD GPU before so I thought this happens after I have switch to an Nvidia one, in between the switch I have not played Java version for a couple months.

Turns out Mojang strikes again.

@IonicEcko

If you believe it should not force quit with Alt+F4, make this a shortcut a graceful exit.

Many other modern games (GTA V, a game released in 2013, for instance) and applications will prompt an exit window if Alt+F4 is pressed, and I accept it as a proper way to ask a program to quit. It's up to the developer to set this up correctly, or allow it with the now errectic force quit behaviour.

Another ridiculous missing feature.

How on earth is a game in 2020 not able to change resolution? Can you just name another not from Windows's store?

First of all, it is certainly not resolved, far from it. Why flag it even before I have responded?

No, I did not keep the window active. Why do I need to keep the window active? I can't leave the game open while I work on something else? And in my own server? This is completely erroneous. If you don't already know, Java edition does not share this bug. 

Mojang likes pretend everything is resolve and turn a blind eye. I guess players should vote with their wallet.

Given the nice attitude Mojang is showing, I will try my best to make sure any potential players know what they are paying for with so called Realm.