Sure you can change at anytime, but it's always safer to not fiddle around with the info too much, as it takes 24-48 hours for the updates to come into effect (points recalculation etc...).
Great to hear about your points! Now that you're sure there is no issue with your eligibility, then it's either a problem with the info you entered. But because that doesn't make much sense since it's been valid for all this time, it's probably a system glitch. It seems many have encountered this same problem here.
Wait for their reply.
If it was ineligible completely, it would have been said so as soon as you submit profile.