If you lock a bee inside blocks it will reach the highest block and stop flying, like literally the animation will stop and the bee will freeze there.
https://www.youtube.com/watch?v=8P03d3H1-_A&feature=youtu.be
If you set blocks above it will stand still on the ground and won't reach the top of the block plus you can see it's trying to fly for a while..
https://www.youtube.com/watch?v=6AXoCyMho4s&feature=youtu.be
Thank you for your report!
We're actually already tracking this issue in MC-159350, so I resolved and linked 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 in the future to see if the issue has already been reported.