This is normal — it means people scanned your code but didn't complete the sign-up. A scan is counted when someone points their phone at the code; a signup is only counted when that person goes on to create an account (or submit your landing-page form). So "3 scans · 0 signups" means three people scanned and none have signed up yet — not that anything is broken.
If you're getting scans but few signups, try pointing the code at Portal sign-up (fewer steps), or make the offer on your marketing copy clearer.