Blocks sometimes disappear when placed

How close are you to the blocks? Is you are too close, they will not place. If you stay away from the blocks after just placing them, they despair. 

like PC, you cannot be right against a block in line with the one you are placing. Back up a tad bit and it should place like normal. If it isn't, then it would be bug. I personally have not encountered this issue.

I don't personally think that I was too close to the blocks but I could have been

Gavin Forstrom I didn't count the number of blocks but I think I was 1-2 blocks away when I encountered the bug

Hmm... may be lag or the world itself. 

That happens to me too, my phone have 1.5gb ram but the 1.14.60 works perfectly fine, this new versión is so lag and have so many bugs

So it could be lag spikes. I never have that issue given my phone has 6GB ram.

I could see lag spike but could also see it as a bug but I don't know 100%

Pretty sure I have 2GB of RAM and am experiencing this, whether it is a bug or it is lag spikes

I have experienced something like what is described when placing blocks in redstone builds, so I think it might have something to do with the block being powered or the game updating redstone maps. It certainly has nothing to do with lag. Does that match what others experience?

I am setting this report to Awaiting Response until we get a video or more precise steps to reproduce the reported behavior.

[Mod] GoldenHelmet That's happened to me. However, the original report was unrelated to redstone.

I will attempt to take a video for you guys.

Where are you attempting to place the leaf block after making the giant spruce tree? The only way I could get the leaf block not to place is by trying to pace it in a spot where my collision box is overlapping, but that that's expected behavior. You can't place blocks with collision boxes that overlap entity collision boxes.

It can be seen that the block does not place (don't mind the cuts, either way it couldn't upload)

Can anyone in beta reproduce this in 1.16.210.59?

Tested it in the 1.16.210.59 beta and still happens but with less fequency. It's mostly solved

1.16.210.60?

The reason I ask is because I am not part of beta, so I need others to test it who are in beta.

Still happens in 1.16.210.60

Can anyone in beta reproduce this in 1.16.210.61? I suspect so since nothing like it was in the changelog but could someone check?

Still happens a lot more in 1.16.210.61 beta

Could someone test it in 1.16.220.50?

Since this is confirmed for the current release version, it is not necessary to confirm every beta. The report will remain open as long as it affects the current release. Adding affected beta versions to the ticket will not change how Mojang deals with it. Adding affected beta versions is only helpful if the bug started in a beta or was supposed to be fixed in a beta but the fix was not effective or reverted. At this point the comments are getting spammy so let's leave it to the developers to address.

I do want to add a new observation about placing comparators, where I often experience this bug. It seems that I cannot place a comparator when my head is right next to the spot where I want to place it. It is as if when placing a comparator there is a check for collision that extends beyond the width of the space where I want to place it. When I move away just a bit so that I am no longer touching the block that the comparator will sit on, then I can place the comparator. Video demonstration:

Thanks for the update!

Issue is worse in 1.16.210 release, at least when playing on a Realm.

Maybe set your Random Tick Speed back to 1? That tree grew instantly, which means your random tick speed was high. That will cause lag, such as not being able to place blocks.

I am reproducing this reliably in 1.16.210 with randomtickspeed 1. A video has been attached!

According to duplicate reports, this affects all gamemodes

I was able to reproduce this issue when crouch placing a hopper into a chest (in mobile btw). When i crouched placed the hopper, i accidentally opened the chest, but at the same the hopper was placed as well. And after when i placed a second hopper facing into the first, the first hopper disappered including the second one as well! I encountered this issue in 1.16.221.

Is that happened because the block collided with the player(relates to MCPE-155353)?

Attached two extra videos of this bug to the ticket, courteousy to ibxtoycat on X for them. This is definitely a pretty serious death bug that I hope Mojang looks into resolving before hardcore. 

A big thing users have reported with this bug is that if you don't hear the block placement sound when you place a block, that means the block is about to disappear, you will notice this to be true when watching the 2 videos I attached to the ticket with volume up. 

This should be considered a critical fix before Hardcore releases due to clips such as this: https://old.reddit.com/r/Minecraft/comments/1d4mgov/i_hate_this_game/

An instant lava death due to ghost blocks is not the Hardcore experience players are looking for.

I have found proof of this bug occurring on Minecraft Bedrock 1.21.31 from the clip in this Reddit post: https://old.reddit.com/r/Minecraft/comments/1fva1fc/bedrock_moment/

This clip can also be viewed on XboxReplay, proving the clip was recorded yesterday: https://xboxreplay.net/gameclip/lid-901f1c8f7bd25-e7521d76c4154915a758a91819b986160

According to the original poster, this clip was from an offline world, so a bad Internet connection was NOT the cause of this bug.

I trimmed and attached the clip to this bug report. The clip is named ghost_bridging_1_21_31. If this bug makes it to the full release of Hardcore, the results will be disastrous.

What I've noticed with this bug is that the blocks are placed but they are placed after 2-4 seconds. Having a small, almost imperceptible drop in fps.

One theory is that when the bug occurs, you might notice blocky transparency, as if the chunk couldn't load properly.

For example, the Overworld, Nether, and End all have this issue every 40-60 seconds. Which makes it a problem in construction, for example making a small bridge in the Nether or End is dangerous.

Diagnosed since 1.16 and still present in 1.21.40-41