If you set a grid display with a white background, the highlighting of the placeholder text disappears which is reported in feedback as confusing:
A simple solution is to always put a lightgrey border around the placeholder block when the grid option is chosen, ie add
border: '1px solid lightgrey'
to the wp.element.createElement parameters in line 209 of js/u3a-event-blocks.js
If you set a grid display with a white background, the highlighting of the placeholder text disappears which is reported in feedback as confusing:
A simple solution is to always put a lightgrey border around the placeholder block when the grid option is chosen, ie add
border: '1px solid lightgrey'to the wp.element.createElement parameters in line 209 of js/u3a-event-blocks.js