how to change the height of event box

It seems my event boxes show time 30 minutes more than it is specified. Is it a know bug?
Is there a way to correct this.
The 20 minutes event is displayed correctly. Others display less than what is specified.


There is a setting which limits minimal height of event box ( so very small events will have a bit bigger height - to make their text visible ), but it must not affect bigger events.

If issue still occurs for you - please provide any kind of sample or demo link where it can be checked.

I set the minimal height. It only set the height of the 30 minutes event. but when the time increases the margin of error (of time) increases. plz Refer to the screen shot day 27. I am working on a demo. Please give any suggestions to correct.

There were no similar error reports, so it hard to suggest anything.
Issue can be caused by custom styling ( events on screen shot are differ from the default one ) - try to remove custom styling or|and custom templates.