This still happens to me:
If i add a launcher to the panel by right click - add to panel and then right click on the new launcher and choosing “move” there is at least a 1 / 3 chance the panel freezes so I have to kill it.
If I just create the launcher and then go into Panel Settings and reorder the items on the panel that way it always works.
Anyone else have this problem? It never happened in 4.14 for me.
I just tried it several times and no problem for me.
This sounds random enough to make me think it could be a theme issue…
Can you run the panel in a terminal and see if it produces any useful output?
geek @ ~
>> xfce4-panel
(xfce4-panel:6938): xfce4-panel-CRITICAL **: 18:49:59.400: Name org.xfce.Panel lost on the message dbus, exiting.
Is that showing the issue with the freeze?
That kind of looks like an internal segfault of some sort… or dbus is crashing… 
NAh, that is just now, running as-is with it already started, obviously.
I am hesitant to provoke it since when I ran 5.10 with NVIDIA drivers it froze the entire computer, no response working except hard turn off. (This is the reason I now run the Noevoue drivers instead and so far it has only locked the panel).
Just Ducked the error code: That apparently is specifically the error you get if Xfce panel is already running, so we’re good there.
In Manjaro and Mageia I have problem with freeze panel. It become freeze when I add random icons from whisker menu to panel.