Is your GPU only from a couple of years ago? That can't be right. Open up task manager while you play the game and see which resource is being consumed the most.
Appears to be fixed in 1.16.201 Hotfix
Windows 10, 1.16.201, I am able to easily pick up fishes with an empty bucket, but not a water bucket
Invalid
Present on 1.16.201
Can confirm for 1.16.200
I think this is intentional.
Only one bug per report is allowed.
Duplicate of MCPE-101202
Duplicate of MCPE-101202
Duplicate of MCPE-101202
Duplicate of MCPE-39299
Try pressing Win+R, then typing "wsreset", then pressing enter and waiting.
Cannot reproduce on Windows 10. Remember that not all blocks should insta-mine, if a block should be instantly mined depends on your tool and the block's hardness, and the wiki can certainly explain this better than I can.
@Patryk Cichy Are you sure that isn't MCPE-55185?
Try pressing Win+R, then type "wsreset", press enter and wait.
Duplicate of MCPE-48036
Only one bug per report is allowed.
I have a similar bugs with beds. The bed was completely invisible until I broke it and placed it back. After I moved it 1 block, the bug stopped happening.
This only happened to me on one world, which (may be coincidental) a guest joined, but it happened to a regular account, not a guest.