Hi! I too had an near identical experience with Citi! I had been looking for a 3rd Secured product to maximize reporting efforts. I had just previously did an App for the Discover It Secured and the Capital One Secured. Approved instantly for both! Have both cards already and loving life. I did the App for the Citi Secured back on March 17th, and received the standard 7-10 day blow off. I waited, optimistically, for nearly two weeks. Finally called in after a week plus and was told they needed to verify my income; which I graciously did. One week later I called the backdoor number again and was advised of the decline. "Debt to Income Ratio". Huh?
So, unfortunately, it didn't work out. While waiting though, I decided to not keep all my eggs in one basket and reached out to US Bank Regarding their Harley Davidson Secured Visa. I have no interest in Harley Davidson, but US Bank does have a nice product line that could compliment my strategy long term. Also, the Harley Davidson card does not have an AF and you earn Harley Rewards. Hey, it's something to Citi's nothing. Maybe I'll get a tee-shirt or something.

Did the App on March 26th, immediately got the 7-10 blow off from them as well. Discouraged, I decided to not think about it and let whatever is to happen happen. Two weeks after the App my deposit was drawn! One week later (today) my HD Visa arrives in the mail. Literally 3 weeks to the day.
I was a bit bummed to not get the Citi Card because I wanted it so bad. But it takes forever and a day to graduate (min 18 months), and has literally zero rewards.
Give your business and hard earned money to a bank that is willing to take a chance and work with you during your rebuild. I'm very happy with my Discover It, Capital One Platinum, and newly arrived HD Visa.
Good Luck!