Hi, Piperboy
I've never used the 496 but the 500 instead. On the 500, we have the "susp" function that stops the wp sequencing when in appch mode ( in case a hold is required at FAF)
Make also sure that you are still in the LNAV/VNAV mode (it will be automatically inhibited if you select the DCT mode)
This applies for the 500, but I'm sure the 496 shouldn't be far from this logic.
Just in case you don't know, you can download a very good "simulator" and a user manual on the Garmin site
Good luck !