Minecarts breaking when turning around a cauldron full of lava

The bug

When pushing a minecart into a turn with powered rails around a cauldron full with lava, the minecart pops off the track. I assume this is because the hitbox of the minecart intersects with the lava's "damage zone.

How to reproduce

1. Place cauldron. Fill with lava.
2. Place a powered rail facing perpendicularly away from it. Create a track around the cauldron.
3. Power the powered rails. push mine cart along track.