If you attack with a brush, the animation will keep playing until you change with another things in your inventory (sometimes this wont work)
If you change with a block and keep moving ,it will (sometimes) automatically place the block. This is an old bug (sorry if my English is bad, i'm French).
Video link (Google Drive) : https://drive.google.com/file/d/1GxxLVD9zu-8BEXL2cqJxHeba8QJjnIVX/view?usp=drivesdk
Thank you for your report!
We're tracking this issue in MCPE-169844, so this ticket is being resolved and linked as a duplicate.
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