When a Text Display entity is created in the world, and if see_through is set to true, a particular anomaly/bug with the lighting of the text display can be seen.

So far, I've noticed that ticking entities and ice blocks render through to the top layer of the text display when no other block behaves this way. (See ice blocks and bee entity in screenshots). 

I found this bug to be persistent across the 1.21.X series, including, at the time of opening this issue, Minecraft's latest version, 1.21.3. I suspect the bug has been present since the introduction of Text Displays, but this has not been tested. 

This is the command I have been using to create said Text Display:

/summon text_display ~ ~ ~ {billboard:"center",see_through:1b,text:'{"bold":true,"color":"red","text":"Hello! This is an example text.\\nAnd this is a second line!!!!!!"}',background:-520093696}