(Sorry, mistakenly posted this in the X8 forum originally)
Three simple objects (ie. 3 solid squares).
I select each of them by holding shift while clicking on them.
I drag them to a new position.
I press CTRL-Z to undo.
The three objects move back to their original position. Great.
Apply a drop shadow to the first object (ie. small glow).
Repeat the above steps.
The first object moves to its previous position while the other two remain in the new positions. I can continue to press CTRL-Z and move through the undo levels but those two objects never return to their original position. My only choice to to reposition them properly again myself.
Now if I apply the drop shadow to the second object instead of the first, and I repeat the above steps, the first two objects return to their original position and third doesn't.
Every object in the selection higher in Z-order than the object with the drop shadow gets left behind.
If objects with dropshadows are grouped, this behaviour can be a nightmare and it can require a lot of effort to fix. This can be repeated on a new document.
I'm running Corel Photo-Paint 2018 v20.1.0.708 on Windows 7 with an NVIDIA GeForce GTX960, i5-4690, 16GB RAM.
When you select the drop shadow object does the property bar say control object or drop shadow group?
Sorry, not sure where it should be displaying "control object" or "drop shadow group"?
Certainly interesting behavior I never ran across this before.