After printng several models and posting reviews, i can no longer post reviews but i can still download and print models.
Some designers require a minimum level to allow you to rate their work. It’s also possible that the creator has blocked you from rating their work.
Boosts aren’t infinite: If you run out, you can’t give any away. Then you’ll have to wait until MakerWorld gives you some new ones.
If this doesn’t apply to you, please describe the situation in more detail, including screenshots.