Missing options in “Twenty Seventeen”

Hello,

I have found some related topics but none with anything near a solution.

I upgraded a website to “Twenty Seventeen” Theme and was able to assign 5 pages to the front sections. But know this option vanished, so I cannot change anything anymore. The “Theme Options” Button is completely missing. Also missing are the little blue pencil icons in the previews and the option to add a video to the header.

I have set a static home page and also set the option to display it.

I do not have too many plugins installed and for sure none was added between setting the sections and no not being able to do anymore.

The only thing I did, not sure if this was in between the two timestamps, was updating from WP 4.9 to latest 5.4.

I did delete the theme, reinstalled it, no luck.

Any help is much appreciated.

Carsten

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