New "barrier" particles behavior is glitchy.
1) They still appear for a short time when barrier block is destroyed.
2) They still appear for a short time when you changed inventory slot.
3) They still appear for a short time when you changed gamemode from creative to another one.
4) They are rendered like particles and are transparent when a block with transparent texture is behind them.
5) They don't disappear at the same time, some particles can live longer than another ones.

Generally, they spawn and despawn with unneccessary delay.