Glowing items don't glow when dropped as an item. Works on Glow Ink Sacs, Glow Item Frames and even Glow Squid Spawn Eggs.
For more info, check the screenshot.
What I expected to happen was...:
They would glow when dropped as an item.
What actually happened was...:
They only were ass bright as their surroundings.
Steps to Reproduce:
1. Get a glowing item (e.g. Glow Ink Sac)
2. Drop it
3. Look at your dropped item
->❌ The item isn't glowing.
Can confirm however, this is most likely invalid as this appears to be a feature request.