Not sure how to get files from the Switch to my phone so I posted the clip to twitter.
This occurs when you Silk Touch leaf blocks off of trees. I think it may be similar to the mushroom Silk Touch issue
MCPE-43720
Silk Touch Leaf blocks dont stack
Resolved
Duplicate
1
Travis Wilde
(Unassigned)
Unconfirmed
Nintendo Switch
1.10.0
Retrieved
Thank you for your report!
We're actually already tracking this issue at MCPE-41408, so we will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.