I right clicked on a clip, went to properties, and changed the speed to .8, that worked.
Then a problem started. Every time after that when I tried to change the speed of the same clip, Shotcut would crash.
Now, when I change the speed of the clip, it simply reverts back to .8 without keeping my changes. I have tried reloading the project multiple times and have tried clicking out of the speed window and hitting enter in an attempt to get the new speed to stick. No avail.