I have been using Dash-to-Dock on Ubuntu 18.04 since April and updating my installation regularly. Recently the icons in the Dash-to-Dock (the ones in the screen that open when you click "Show Applications", not the ones in the dock) change size without any warning. Sometimes they are big, sometimes medium and sometimes so tiny I cannot identify the app from them.
Below is a screenshot.
I know how to change the size of the icons in the dash but cannot find a way to alter the size of the icons in the application screen.