I also was using N1MM / MMTTY and had the same hesitation, but I noticed that it only happened when I had the mouse hovering over the Receive window of the Digital Interface window, and it never seemed to happen if I had the mouse in the right hand end of the window, and away from any received text.
At the same time the green bar at the left side of the window would turn yellow, as if I had pressed the green bar to cause the window to pause.
I run 3 decoders, MMTTY as Primary, GRITTY, and 2 Tone.
Upon review, somehow I just discovered that I now have checked in the Settings listing to "Use RX Window Callsign Pause Routines". I didn't notice this prior to this message, and I don't remember ever having selected this option.
Perhaps I accidentally checked it while adding additional RX windows.
I run a Windows 10 Pro computer, 8 GB RAM, Core i7 processor running at 3.2 GHZ.
All that I needed to do was to move the mouse pointer out of the receive window and the window would re-activate within a second or 2 and show me the buffered text, so it was more of an annoyance than a real problem, but sometimes, it would only display a partial call when it paused function. Clicking the yellow bar at the left side of the window would immediately return receive function to the window.
So, the problem here may be one of operator error.
Excellent program and superb support by the developers.
73 de WA3ZSC - Jerry