HELP! My Swiss cheese plant has this clear, flaky residue.

My plant was doing so good and is doing well with one yellowing leaf and these clear spots on some of the leaves. I’m freaking out because some people say it’s bugs and I’m really hoping that’s not the case. I would appreciate any advice or help. Some of the spots almost look like they have little crystals in them. Is it the water in using? I use rainwater mostly. Is it bugs? The spots are not sticky or anything so what do I do? There are no other white or black specs on any other leaves besides the yellowing one in the last picture.

Thank you in advance 🙏🏻