Anda que no/si
 

Hi,

It looks like the subj basically means yes, never mind si or no. Is it so? From Context Reverso:

Anda que si lo sé.
Don't I know.

Y anda que no lo sabía.
And didn't she know it.

Besides, Context Reverso output depends rather heavily on whether it's si or sí, so I am not sure which is the right way.

The word 'anda' can be used to express surprise, encouragement, disbelief, rejection, admiration, irony, and to give emphasis.
I believe this is used in Spain.

Here it says more about this usage and gives other variations that can also be used. I heard some of the variations used in Central America.

La palabra 'si' no lleva tilde.