display bug on grid

I updated from version 5.0.5 to 5.0.6 and the event font size in the grid style calendar is randomly changing. I can’t see any logic to it. I have reverted back to older versions .5,.4,.1 and it didn’t go away. Very frustrating. I deactivated the bonus add-on in case it was involved, but I don’t see any difference. I am now just going to go to yesterday’s back up and hope that works which means I lose all of today’s work. The link above is to my staging site.

The page I need help with: [log in to see the link]