Equation stays unchanged for different configurations

HI, I am using Solidworks 2023 sp1 community version.

 

I crated a simple sketch, dimensioned a hole with equation set to D1@Sketch1 = "10mm" + "Tolerance", where the global variable name "10mm" has value of 10mm, and "Tolerance" has value of 1mm.

The hole diameter in its default configuration has, therefore, 11mm.

 

Now, I create a new configuration, called config2, in the "Equation" Table, I select the top right corner from default to "config2", I then change the equation for "D1@Sketch1" = "15mm" + "Tolerance", where "15mm" = 15mm, after rebuild, I see the hole diameter has size 16mm, so far so good.

 

However, after I switch back to "Default" configuration, the Equation for "D1@Sketch1" remains as "15mm" + "Tolerance", I expected it change back to "10mm" + "Tolerance", is this a bug in the software, or am I misunderstanding how Equation and Configuration work? 

 

Thanks

equation