"Double Click To Isolate" preference does not work
Using the direct selection tool to try and double-click your way to grabbing a grouped object within another group of grouped objects fails. It simply doesn't select any of the other elements. This is a paralysing bug that may well see me dumping my CC subscription and going back to Illustrator CS5 or 6. From what I read, this bug is old so why hasn't Adobe fixed it?
Attached is the file with the bug. Try double-clicking the green nodes on the chart with the direct selection tool. It should grab all the dots. Then expand out and grab the other grouped elements. It does not.
I'm on the latest version of Catalina using the latest version of Illustrator.
Hm. Direct Selection tool does not allow to isolate at the first place, and never was able to.
Selection tool (with the corresponding option on) allows it, but corner widgets don’t get displayed when ordinary Selection tool is active, so I guess your assumption is wrong, both of them... but you say turning widgets off helps, and this is not something what I see when I try to replicate it.
There is also a Group Selection tool (as a separate tool or the the Alt/Opt-mode for a Direct Selection tool) — it selects the parent object, going up in the hierarchy with every next click — but you don’t mean that either.
So... I have no idea why you try to isolate with double-click using Direct Selection. Why did you think it does? Does it really work for you?
Im dealing with this garbage too.
Graphic Gibbon commented
I think I've solved this myself. Because the nodes are small shapes, when I was clicking on them, I was unknowingly clicking on the Live Corners Widget dots. By turning that off in the View menu, Double Click to Isolate works again. A classic case of Adobe adding a new feature that actually interferes with a critically important base level feature.