Hi Mike,
Unfortunately I’m pretty sure that this is not a bug in the nodes but a ‘feature’ (
) of a design choice made deep back through the mists of KNIME time which has an unfortunate consequence with branch switching (my guess is that is pre-dates the possibility of inactive branches - maybe @wiswedel can remember?!). There is an explanation better than I can give here - Case Switch Flow Variable Problem - #8 by LukasS
In terms of a workaround, then your best bet is to do the manipulation(s) on the variable values in a table - possible via a Variable to Table (Row|Column) node, and then convert back to a variable after the End If/Case.
As mentioned somewhere higher up the thread above this used to be explicitly explained in the old Variable End IF and Variable End CASE nodes when we first released them. As much as I love KNIME as a product, this is very definitely one of my least-liked “features”!
Steve