After search, Related posts not 2 column anymore

Hello Support,

related posts working like a charm,

Heizkörperventilatoren

but after I useing search and click on one of the post results, at the end, the related post view aren´t 2 column anymore. Its a one column and the image is to small for it. Also some code is shown at the end.

Badheizkörper: Arten, Vorteile und Kaufkriterien

I can´t found the option where I can supress this behavior.

Do you have any hint where i can look into to make it 2 column again, even after I search something?

Thank you.Cheers

Markus

You can test it here: https://www.heima24.de/wiki