I have been using SwiftKey since yesterday. Bought it on sale awhile back and never used it because I had google's stock 4.0+ keyboard on my last phone and it was great. The keyboard Samsung gives is so terrible I am so happy I bought SwiftKey and set it aside just in case.
Anyway, I'm using the paid version of nova and I have yet to experience this, but I just got the phone on Monday, switched to nova (which I had been using for the longest time on my previous phone, hence paid version) on Tuesday, and switched to SwiftKey on Wednesday. I'll report back if I do experience this at any point, but until then I definitely recommend the paid version of nova launcher. Always a good thing to support the devs if you like something and want to see it continue to improve.