Composer issue - Alignment between headers and textblock

Hi Stackideas,

I have some problems in the correct alignment of my text and headers.

I have just a clear post with the sequence header- text - header- text - header -text.
However, the alignment differs per paragraph (see example).
And further, I cannot align a header just above the associated text. There is always some white space,

I suppose I am doing something wrong, but I cannot figure out what !??

Kind regards, T. W. van Urk