Impossibility to change the preset font sizes of the paragraphs

Hello! For a week I have not been able to change the font of the paragraphs from the preset options (small, normal, medium, large, huge). I do not understand whether this problem is only with me, or others have this problem. Will the problem be solved and when? I specify that I have not touched anything on the settings of my wordpress, so there is no way I have caused this problem. Otherwise, if I write a number manually, the font changes, but I also need the preset sizes.