Starting with
which has an error in the timeline because on feature cannot be added when x_units is 1, but is necessary and works fined when x_units is > 1.
When I change the expression for y_units to 3 and hit tab, the recompute happens and the body in the workspace changes to reflect the new size, but the value for y_units does not change in parameters. The the error message for the pre-existing error opens, although given that it doesn't have anything to do with the parameter being changed and it does not stop the body from being shown at the new size, I don't know if it is at all related to the parameter issue.
If I close the parameters and then reopen them the expression has been computed correctly and is now 4.
Changing the x_units to 2 will clear the error, and in that case the value field updates immediately.
Given that the value doesn't even require any computation of an expression when the expression is a literal, and that when the parameter dialog is closed and reopened everything displays correctly, I have to think this is just a bug where the error dialog being shown somehow interrupts the display update of the value field in parameters.
I would expect that a change in a parameter update all dependent parameter values before anything else happens, including recompute of the design.
