Hi,
Not sure if this is an actual bug or just me not using the GUI editor correctly.
Here’s a video showing the issue. It won’t always jump around but more often than not.
Using 2.7.14 for Cabbage, Csound 6.16.2, macOS Catalina 10.15.7
Wasn’t sure how to correctly do the blockquote, the preview was looking kinda weird so I uploaded the .csd.
2.PingPong_IJLV.csd (1.7 KB)
The problem here is that you have two widgets with the same channel name. Channel names in Cabbage are really important and must be unique for each widget. If not, you get this confusion in the GUI editor over which widget you are interacting with. I had a warning system in place for this, but removed it due to uproar in the community about Cabbage spamming 
You can avoid this kind of issue if you a) don’t give labels a channel at all, which will result in Cabbage assigning a unique name for them, or b) get into the habit of giving each one a valid and unique name.
Got it! Thank you so much!
