Glo Justification Switch Works on some Epub

I just got the Kobo Glo, which is very nice. However, there is a problem with the justification switch. I would like to have sometimes right justified, and sometimes ragged right.

Some books in the library allow that. That is, with the "justification" switch in Aa, you can have either left justified or ragged right. Other books have only one or the other, no matter the Kobo switch is set.

In calibre I can "epub to epub" covert to either one. However it does not allow the Kobo Glo to do that switching. I have tried ticking all boxes in the Filter Style Settings and that does not work. Sigil seems to have the same inability to fix this.

Looking at the CSS in the Search and Replace box, I find only one instance of "text-align" and that is "text-align: center." In the whole book only one instance on the first page.

All of the other books that are only left aligned or justified have the exact same instruction, "text-align: center." I can see no difference?!

What can I do to allow Kobo Glo to activate the justify switch????

I am sorry that I am not familiar with CSS, so some detail on what to do is much appreciated.