I recently added a 4th display and started encountering an issue. When changing profiles displayfusion stops responding.
Here are the profiles for reference:
Profile 1
1 XB271HU - Enabled
2 Kamvas 13 - Disabled
3 E320VL - Disabled
4 VE228 - Enabled
Profile 2
1 XB271HU - Enabled
2 E320VL - Disabled
3 Kamvas 13 - Cloned 3/4
4 VE228 - Cloned 3/4
Profile 3
1 XB271HU - Enabled
2 Kamvas 13 - Disabled
3 E320VL - Cloned 3/4
4 VE228 - Cloned 3/4
I can change from 1 to 2 or 1 to 3, and then back to 1 without issue.
Attempting to change from 2 to 3 or 3 to 2 results in the issue. Also the monitors labeled 2 and 3 swap numbers between Profiles 2 and 3 for some reason.
If I attempt to load the profile through the Monitor Configuration window. The 4th monitor becomes enabled, but the cloning does not change. The Monitor Configuartion window then stops responding and windows will ask me to close it. I can then reopen the Monitor Configuration window from the taskbar icon again.
If I attempt to load the profile through the Monitor Pofiles option. The 4th monitor becomes enabled, but the cloning does not change. Display Fuision stops responding entirely and must be killed through Task Manager.
I also tried to create a 4th Profile with monitors 2/3/4 being cloned, but this fails regardless of the profile when I attempt to apply it. I can apply this setup through the Nvidia Control Panel though.

Additional Info:
Windows 10
All 4 Displays are attached to my GPU

Uninstalled 9.9 and installed 9.5. Recreated the profiles. All profile switching worked correctly. I was even able to create the 4th profile with 3 cloned monitors and switch to it without issue. The monitors also stopped switching numbers when changing profiles.