Dear Matt,
Thanks for your reaction. I have changed the theme to twenty fourteen. We also only use plugins we also use in different websites, so really strange.
Is there a standard setting that could be disabled or something in the code?
Hope to hear from you.
Ok we did find the answer for this question:
Open week.php (in the template file) and look for the code
left: <?php echo $indent * 8 ?>px;
The 8 is the 8px left and because it is just 8px you can not see the event behind it. We changed it to 30 so:
left: <?php echo $indent * 30 ?>px;
Now we can see the other event
