If the white clouds sink as soon as they stop swimming and they struggle to swim up, that can be a swim bladder problem.
If the fish struggle to swim down and automatically float up when they stop swimming, that can be a swim bladder problem or air in the fish's intestine.
Fish that are fed a lot of dry food or food at the surface will regularly take in air along with the food. The air then has to work its way through the digestive tract before it comes out the back end (yes fish fart). Once the air passes out of the fish they can usually swim normally again.
Air causing fish to float is very common and can stress the fish. The easiest way to see if air is the problem, is to stop feeding dry or floating foods for a week and see if the fish improves. Frozen (but defrosted) foods and live foods can be used for a week and if air is the problem, then continue with frozen or live foods and give them some dry food a couple of times a week.