The only way you see activity logged to a known lead in Marketo is if (a) the person allows the Munchkin cookie and (b) the Munchkin session is associated.
The Munchkin session can be associated in a few ways:
- opening a Marketo email link with the mkt_tok query param or
- filling out a Marketo form or
- other API-driven association (unlikely to be used in your case)
These associating actions need to occur in every browser profile independently. That is, if you open a tracked link in Safari on your iOS device, this doesn't affect a still-anonymous session on Chrome, even on that same phone.
In addition to Sanford's explanation I seem to understand you are testing with multiple email addresses. If you are doing that from one device, you need to be very aware of which record has gone through associating the cookie last, as there will be only one cookie and depending on your link clicks and form fills the cookie is associated to only one record in your database (the last record you filled out a form or clicked on a link with).
So you need to write some good test scripts where you make sure to take the right steps in sequence to test the behaviour you want to verify. It might be wise to remove cookies altogether before you start testing with a new email address.