New + Existing roommates = new lease or continuation?

[Mark Ko]

I signed a 6 month lease with my tenants two of whom were living there last year and one is new, moved in after one of the old roommates left at the end of last lease.

This typically is not a problem except in Portland which sets a cap on rent increases of <10% per year. And in all the documentation I've seen I don't see any mention of 6 month lease. The phrase "rolling 12-month period" appears over and over.

My question.. and I understand there may be no clear answer to this. I have a appointment with a lawyer coming up next week.

Is my current lease a new lease (hence the year long cap doesn't apply at month 7) or would it be seen as a continuation? 

Thanks all, just trying to work through a tenant issue.