On Calc under Fedora 24 KDE Plasma if I select a group of cells using left mouse and dragging over the cells, I am unable then to single click on other menu items, e.g. I can’t select a 3x2 group of cells and then format them using the mouse. However I can select the same cells using the keyboard without preventing subsequent mouse actions.
Having frozen the mouse click/block of cells in this way, I can then unfreeze it by selecting a whole column, whereupon any keyboard changes, such as delete, ctl-C or ctl-X, to the previously selected cells are displayed and the mouse is active again.
The problem arose immediately after upgrading FC24.