Summary:

This error is very similar to MCPE-116767, except that only glass, slime and honey block are blinking in front of the ender portal ...
Also, a barrier is not displayed against the background of the portal's ender (it does not blink, but only stripes remain from it).

Steps to Reproduce:

1. Activate the ender portal.
2. Place a barrier over it, a block of mucus and honey, glass.

Observed Results:

Blocks flash (and the portal disappears altogether).

Expected Results:

Blocks behave normally.

Video:

Block.mp4