If you have confirmed their status as Active in the REALTORS® M1 database, but they are showing as Inactive when they log into the main NAR.REALTOR site, they may be logging in as a non-member Guest, rather than as a Member.
Please have your member reach out to Member Services at contactnar@nar.realtor for confirmation and assistance with converting their guest account to a member account associated with their Member ID.
For example, here is a screenshot comparison of "My Account" on nar.realtor, with the left being a guest login and the right being a member login.