New Post: Stylesheet Classes & Co. without effect

Hello,

Values from the Link-Panel, last Tab, are not applied:
Stylesheet Class, Title, Style, ...

DNN 7.4.0 / CK Editor 2.1.0
and
DNN 7.3.4 / CD Editor 2.0.14


Another Website without Problems:

DNN 7.3.4 / CD Editor 2.0.11

Can anyone help?
Thanks, Manfred