I am getting extra space in the header while using column repeating layout. It seems the space is coming from the delete icon which comes by default as a part of repeating layout and i have deleted that icon as it is not needed for our purpose. Please refer to the document for more details.
As per the screenshot shared it looks like you had not removed the blank column which is available in the first column, could you remove it and have a try. If not please share the final configuration of your repeat grid and the output screenshots.
I just noticed that there was some customized style was added in UserWorkForm CSS specific to column repeating layout which was somehow causing this blank space to appear in the header. Sorry for the inconvenience caused.