It is currently not really possible to mouse-select code from the coreui docs with Chrome and Edge. This is the case for some weeks now, but did work before, so some change must be responsible. It works with Firefox though.
Example:
https://coreui.io/angular/docs/components/dropdown
- First example code of "Single button"
- Position the mouse before the <c-dropdown element
- Left-Click and try to select the whole block by moving the mouse
- Result: The selection immediatly jumps a page down and the whole content between is selected
By futher testing it is possible to just click before the <c-dropdown element and shift-click at the end of the block. This selects the block correctly.