After upgrading a site from U7 to U12, we have found a strange "bug" where multiple RTE menus are not showing for existing (and sometimes new) content in a grid layout.

The first RTE menu is displayed in the content editor, however, if there is multiple RTE's in the same editor (say for additional content), only the first RTE menu is showing.

As a secondary issue, line breaks also does not seem to work, we can add a linebreak but on save all content seems to be merged "inline".

I have made a quick loom video to illustrate. We're running U12 for reference, and I can confirm that on U11 this worked as expected (we still have a demo version of the same site that ran U11 and the issue isn't present there).

Any ideas where to look / troubleshoot? As mentioned console does not show any errors accept for an apparent missing angular.js file, but this was also present in the U11 version so I am doubtful it's related.

Here is the loom video to illustrate, will appreciate any input we can get: https://www.loom.com/share/538babd99e294abb939f47b8dcd1061d