Glad to see one of my posts is linked on this site. Very humbled, thank you!

Do you get any noise, like the motors trying to work?

Presume they don't fold in and then back out?

And yes, you may have the button (next to the sliding one) but could be that the complete mirror housing has been swapped for manual fold one's. Hope not though.

Get the back off the mirror and you'll know immediately. Plus check the fuse - numbered in the glove box.

Sanj