This bug report is a parity issue with Java.

Summary:

The placement of the Glow lichen in the Java version occurs first on the sides where you aim closer. That is, first at the side you are directly aimed at, and then at the nearest sides. In the bedrock, the glow lichen is always placed on the same sides.

I think it will be a little clearer if you watch the video.

Steps to reproduce:

1. Start placing glow lichen (several in 1 block).
2. Watch how you place it.

Observed results:

The placement is always the same. First on the side you were aiming at, then on the horizontal side (if you were not aiming at it), and then in turn...

Expected results:

The placement will be first on the side that is being targeted, then on the horizontal side, and then on the side that is closer to the cursor, then on the opposite side, and then on the last one.

Video:

Java Minecraft 1.17.1 - 2021-08-29 22-24-14.mp4

Bedrock Minecraft 2021-08-29 22-26-29.mp4

Image: