It doesn't need to be moved. The display mode for any tab in canvas main middle just needs to be tab menu or nested tab menu for it to properly display there. That position doesn't support any other display mode.

Also noticed that cb_connections.php has not been upgraded to output correct bootstrap 4 html

CB Connections has been updated for Bootstrap 4. You can see it working perfectly fine on our demo site below.

demo.cbdemosites.com/profiles/susan?tab=Connections

If you see any issues please be more specific as to what those issues are so we can review and fix them.

Ok, you're referring to the Connects Path tab. I see the issue and have added a bug ticket to fix for later release.

forge.joomlapolis.com/issues/7242

So I gave up on using canvas main right and canvas main right. And have moved things to "right side" and "left side" when I do not want them in the middle but side by side. It seem to work on a PC

I don't understand the issue with main left and right. Canvas Main Left and Canvas Main Right only display if the FIRST tab available on profile is selected. If it's not those sidebars will hide. If you want your left/right sidebars to always display use Canvas Main Static Left or Canvas Main Static Right. The canvas layout has always behaved this way since CB 2.x and is not specific to the B4 implementation.

Do you have a demo-site where I can see the fields and tabs that goes into the installation version of default CB?

You can demo CB below.

demo.cbdemosites.com/

1. The right side and left side always position themselves underneath each other. Before my last update to the last CB version this did not happen. This also goes for connections. There should be room enough to place 2 connections side by side. I have attached the "right side" content (inside grey frame).
I am stil talking about this page for example: whogreen.com/who/encina-ewa

Because Left side and Right side positions have nothing to do with the canvas layout. Only the positions prefixed with Canvas will display in the canvas layout. Everything else is below it or above it. If you're having issues configuring things run the Canvas Layout tool in CB > Tools and it will force the canvas layout configuration. This has always been the case since CB 2.x released and isn't specific to the B4 implementation.

2. The style for "list view" is the same thing. On a PC you can see the list fills out horizontally but on an iPad all fields goes underneath each other.
here is the list for my main "featured" menu. It looks okay on the PC but not on the iPad. whogreen.com/featured-2018

They are supposed to display under each other as there isn't room to display them side by side. It's responsive so it will collapse down. It should only do that on very small view sizes (phones or likely landscape tablets). Userlist has always behaved this way since CB 2.x was released and is not specific to the B4 implementation.