Seems from other people's experience (and mine), on your 6th statement, you will get a CLI if you use it regularly. I went from 1500 to 2500 just 2 days ago. I'm pretty excited about that. The do not accept customer-initiated CLI's, so you will have to wait for them to give you an auto-CLI. Stick with it, though. I don't know what my score for EX was in January, but now it is 645. Your score is higher than mine, so who knows what gives. Hard to tell with WAMU. They are all over the board.
Scores: TU (FICO8): 781, EQ (FICO8): 798, EX (FICO8): 788
In my wallet: Chase Sapphire Preferred: 16,000 | Chase Slate Edge: 8,100 | Bilt World Elite Mastercard: 16,000 | Fidelity Rewards Visa Signature: 8,500 | PenFed Visa Gold: 12,500 | Penfed Pathfinder: 15,000 | Apple Card: 6,500 | Lowe's: 35,000 | Northern Skies FCU Platinum: 15,000 | Kohls: 3,000
Mortgage 11/20
