playback becomes confused

After changing playback tempo as a percentage and inputting different notes in the score, playback becomes confused, meaning the parts do not start at the same place. When I change the playback percentage again (either to a faster or slower tempo), playback is corrected. But this additional step must be taken every time a change is made to the score. If I wish to return to 100% playback speed and continue editing without changing tempo, I can't do this because after every change of note inputted, playback becomes confused again. How does one return to normal editing at 100% playback speed without having to change playback speed every time an edit is made?

Thanks.