It's the PayPal app. At least that's what did it for me.
Spent an hour on the phone with Samsung tech support and they eventually told me to reset my phone to factory settings. I was very angry because I just bought this phone yesterday and spent the whole day setting it up to how I like it, and now I had to reset it.
After reset, it worked just fine. So I went through the app store and downloaded all the apps I use.... And then it started glitching exactly like the Op said. So I uninstalled app after app until it worked... And PayPal was the last app to go. So to test it, I reinstalled PayPal and kept it checked in S Finder's search settings, and voila, it glitched. So I unchecked it, restarted my phone, and now S Finder works just fine.
Let me know if this helped anyone. I've spent the last 4 hours trying to fix this issue, and it would be nice to know if it helped anyone. If anyone knows of any other app that freezes S Finder, post it here. Samsung needs to fix this.