Summary:
Small dripleaf removes flowing water, thus breaking when placed in flowing water.

However, this may be a consequence of MCPE-139018 "Small dripleaf can be placed in flowing water (incomplete water block)", as placing Small dripleaf in flowing water is not expected.

Steps to reproduce:

1. Place the water block on a flat surface.
2. In the resulting flowing water, try placing a small dripleaf.

Observed results:
Small dripleaf will break very often when placed in flowing water.

Expected results:
Small dripleaf will not break into flowing water when placed.

Video:
Minecraft Preview 2022-02-12 20-48-51.mp4