Help with Clear like Bubble Algae?

I read through most of the posts here in his section and could not find anything on this. I think it Bubble algae but i need to be sure.

They are round in shape and completely clear. Is this considered bubble algae?

I have been in the hobby for a few years and never had this problem.

What should I do?

Tank parameters are normal and I do 2x 5-8% water change a week because I am currently fighting a small Diatom bloom.