This is both soul and funk - but that bass line is definitely funky!
In my experience, most funky bass lines - and most funk tunes in general - don’t have any slap. I think of The Meters or Parliament or even Bootsy - there are more non-slap lines than slap lines.
But I hear you - the line between soul and funk is real blurry at times.
James Brown is both Soul and Funk at 100% all the time.