Hi!
There was a bug in one of the previous versions where these actions you're looking for didn't perform as intended.
This may be the source of your troubles.
This has since been fixed, but i don't remember in which version, so be sure to download the latest.
In either case, you'll find the corresponding action under File > Canvas (.nam or .map) > Save screen as ASM ( or > Save screen as C header).
The options to toggle saving nametable data and attribute table data on and off is in the + options submenu, just below.