Andy;
Why would you think you shouldn't be in ketosis? Next the bacteria in our pores combined with our pore's secretions determines how we smell. If you have changed the composition of your sweat that could change the bacterial interaction.

There are several things you can try. You can try rinsing with some vinegar (no I'm not kidding). You could have changed your bodies ph altering the resident flora so, since we should be mildly acidic, a mild vinegar rinse would assist. RINSE that off don't leave vinegar on ok. That added to your regular routine a time or two maybe just the trick.

If no, try changing deodorants or try an anti-perspirant (it reduces perspirations vs simply masking odor). Try chlorophyll tablets they help absorb odor as well. I believe Charcoal does too though I'm not as familiar with that.

Try this and some tincture of time as well your body, as well as the resident flora and fauna LOL, need time to adjust.
Jo