Snap Area function conflicts with preview.app

I am using BTT ver. 3.562 on macOS Big Sur 11.3.1. I just found that when I activate the snap area function on BTT, preview.app shows the following problem.
Steps to reproduce:

  1. Open any PDF with text in Preview
  2. Search for any term you KNOW the document contains
  • so you can see search results in the left bar
  • Preview should jump on the first search result and show other results in the left bar, pretty normal stuff
  1. after that, click ANYWHERE in the document text
  • like you would like to change focus of the window back to document
  • like you would like to select some word with your mouse to copy that word
  1. Preview immediately freezes and mouse goes to spinning beachball
  2. Force quit of preview.app is the only way to make it work again.

This does not happen when I deactivate the snap area function on BTT.

A similar problem is reported below, but not for BTT, for another window management utility.

unfortunately it’s a bug in preview but I hope Apple will fix it with the next macOS update.

For now you can only disable window snapping for preview.

Thank you very much for the prompt response.