How to set field controls in a "data sheet" style form?

I have created a form using the “Data Sheet” arrangement, which provides a form in a spreadsheet view that looks very similar to the Table or Query it represents. I now want to add controls to the fields in this form. However, when I have the Form Design Mode on, I can not make any adjustments at all to the “Data Sheet” or add controls. The only thing I can do is change the size of the box that contains it. If I turn off Design Mode, I can adjust column widths and add/edit/delete records (as I intend to allow). I have checked to make sure that I haven’t accidentally grouped it with something else.

It is clear one should be able to use controls in a form arranged as a “Data Sheet”, as that is the entire point of using forms, and because I see some tips online (e.g. here) that say to right click on the column header and select “replace with” > “list box”, and I can see for example in this tutorial starting at 5:30) the person is able to adjust column widths while in Design Mode.

I expect I may be missing something simple, but have tried this several ways, starting with a new blank database, following along exactly with video tutorials, and get the same result. I am using LibreOffice 5.0.4.2 on a Mac (Yosemite).

Thank you in advance for any suggestions!

It looks like I am not crazy and this is in fact a bug in LibreOffice 5.0.4.2 as given as an answer to a similar question

and described here:
https://bugs.documentfoundation.org/show_bug.cgi?id=96482
Unfortunately the fix won’t be implemented until version 5.1.