Buttons in Child Theme

i have a problem creating a working childtheme. when using a childtheme a lot of styles changing,
For example, the used fonts are changing and the style of buttons are changing.

I have tried download example childthemes and plugins that should create a childtheme based on the original settings. neither works.

Hi there,
Thanks for reaching out.
In reference to your query here, could you try using this plugin (Child Theme Configurator – WordPress plugin | WordPress.org) to create a child theme. Once this is done, install this plugin (Transients Manager – WordPress plugin | WordPress.org) and clear your transients from the Tools>Transients section.

I hope this helps.
Best Regards,