Primary sidebar not displaying on start page

Hi,
solved. One of the posts wasn’t coded properly (missing closing div).

Here are instructions in these situations, maybe someone will find it useful.

Sidebars and widgets in them do not fall to the bottom and display below posts and/or posts do not appear in sidebars unless

(1) content has been imported into the blog

(2) the blogger has been copying and pasting content from elsewhere, without using either icon 5 or icon 6 in Row 2 of the visual editor https://en.support.wordpress.com/visual-editor/#pasting-text

(3) or the blogger has copied and pasted invalid HTML into a text widget or left an HTML tag open

After you go here and enable this > Settings > Writing
Formatting
_ WordPress should correct invalidly nested XHTML automatically
“save changes”