@label not showing in tooltip of 3-button

Have a 3-button button setup to
left-click : toggle folder tree
right-click: togle folder tree lock

The button is on a toolbar that hides labels and the tooltip shows the labels

which is good and how I like it.
The only problem is the text shown in the tooltip does not reflect the label set by @label modifier.

Please make it so that the tooltip text of a 3-button reflects the label as set by @label (if set)

i.e.
image
image

Do you have the "Dynamic icon/label from child buttons" option turned on for the parent button?

It was off, turning it on had no effect on the tooltip label.
--- in addition having a look again after turning it on and the setting has turned itself off - further investigation results in that setting not being able to be set on.
setting it:
image
click OK and close customize using the tick.
re-open customize mode and button is now
image

We've fixed that for the next beta.