Gravity block floats after breaking End Portal underneath it

If you make an End Portal one block below a gravity-affected block and then break the portal, the block floats.

Steps to Reproduce:

1. Build and activate an End Portal

2. Place a gravity block (e.g, Sand) on top of the portal

3. Break an End Portal Frame

Observed Results:

The block floats.

Expected Results:

The block falls to the ground.