I need this workflow in Inkscape: many text objects of the same style, I change the style of one object, the style of all text objects changes the same way, but the text of all objects are different. I tried cloning, but the text is the same for all objects and can't be changed.
To change the style or attributes of any objects in Inkscape you first need to select them. Unfortunately, Inkscape doesn't have a character styles panel like word processors or page layout software where you can define character styles.
So, with that in mind, here's a workaround.
Assuming your text is contained in separate text objects, select all the text objects you wish to change. You can click and drag with the Select and Transform Objects tool F1, or click on each object while holding down Shift to make a multiple selection, then hit the Text Tool F8. Finally change the styles you want in the Control Bar along the top.
Another possible workaround is to copy one text object which has a style you want, then select the others then hit Edit > Paste Style Shift+Ctrl+V