Yellow sludge in oil cap dipstick m54

[ake53]

Hi everyone, i was waxing my X in the garage tonight and i opened up the hood to check oil. The dipstick showed the oil as black and almost full. About 2k on oil. I noticed a yellow piece on dipstick. Wiped it, put it back in and check again and its there again. Thinking what the heck! I open the oil cap and there is more yellow sludge. Its weird when i took some out and rubbed it, it disappears into black grease.

I did some research and people say its oil mixed with water/condensation.

How dangerous is this and why did it occur.

I replaced oil with full synthetic 5w:30 castrol titanium edge and bmw filter. The X is also garage kept. And drive around 30 miles a day. Sometimes more. But its a daily driver.

What should i do?
Obviously i will do an oil change.