I gave the command /effect give @e minecraft:glowing to try to find some villagers that had wandered off. After finding them, I gave the command /effect clear @e, and nothing happened. I then tried /effect clear @e minecraft:glowing, and that time it said Target has no effects to remove. I assume it thinks it cleared the effect the first time I gave the clear command, but it didn't actually change that all entities still appeared to be glowing. I went into a test world, did the same thing, and it happened again. I also tested this on my character but it seems to be working fine for players.

Steps to reproduce:
1. Create a world in snapshot 21w13a
2. Make sure there are a couple entities around
3. Apply the glowing effect via command (although for me the glitch also happened with spectral arrows in the testing world so you could use that too)
4. Try to clear the glowing effect

Thanks for your time! <3