Increase Editor Height

I checked this and discovered that I have the same problem after nearly 5 years use of this plugin.
I checked on 5 of my sites and it gives on all sites the same problem.
The window of Wp edit excerpt can be adjusted by dragging on the right corner.
I have also a couple of sites with the Pro version same problem.

I checked the standard wordpress editor NO PROBLEM

Addition
Did on two other site test with the standard wordpress editor .
I could not adjust the window height of the editor.
All plugins deactivated.

I want to emphasize that my statement that the standard wordpress editor has no problem IS NOT TRUE.
I checked again on an other website THE STANDARD WP EDITOR HAS THE SAME PROBLEM no adjustment of the vertical height.
I checked the css and noted that the style loaded from the wp-admin folder showed

resize:none if I change that in the browser to vertical the adjustment is back.

This a wordpress problem.

Hey guys… sorry for my delay.

Try this.

1) Go to create/edit a post.
2) Towards the top-right corner of the screen is a tab called “Screen Options”. Click that tab.
3) In the slidedown panel; look for the option that says “Enable full-height editor and distraction-free functionality.”.
4) Uncheck this option.

That option is a default WP option. I’m not sure how it got turned on for you… but turning it off should restore the ability to drag the editor height.