Cannot type in Find in Path for 10 seconds

I'm using IntelliJ IDEA Ultimate (2018.1) for Mac and have run into an annoying problem. Any time I bring up the "Find in Path" dialog, the "Text to find" box is unusable for about 10 seconds. This happens consistently and it's been driving me nuts. Has anyone else encountered this problem? I often want to use Find in Path to find all occurrences of some text, across all files, but every time I do I have to wait approximately 10 seconds before it will let me type my search term. I just did a screen capture to record exactly what I'm seeing, which you can see here: https://www.youtube.com/watch?v=t2_iEZROWgM In that video, I superimposed the "delete" key on the screen every time I press backspace, just to illustrate how it's totally non-responsive. How do I fix this?