Issue with Discover Bank and MFA (edited)

I am trying to connect Discover Bank (savings account) to Quicken. After the sign in, it's time for the verification code. I get 2 options: text to my landline (wrong) or text to my mobile phone. Not a good situation already because a week ago I attempted to connect Discover Bank to an investment account and I would never get a verification code from Discover Bank via text to my mobile phone as many times as I tried. I eventually got locked out of my Discover account for all the attempts. The only way it worked then was to start all over again the next day and choose "call" instead of text. With Quicken, I didn't get any other option to receive a verification code other than text to my mobile phone. It didn't work - no text. So then I'm stuck. And of course, as someone else in the community expressed, you don't get your options back again with repeated attempts - you just get stuck with your original choice. I called Quicken - 'not a Quicken problem, it's a Discover problem'. Long story shorter, I talked with Discover 3 times (5 different people) and U.S. Cellular 2 times - most of those calls with people diligently trying to figure it out - but no evidence of verification requests (3rd party verfication system?) or short-code attempts to enter the U.S. Cellular system. 3-1/2 hours later and getting locked out of my Discover account again - no solutions and all indications falling back to Quicken. After all of these people, I'm honestly still not sure who or what even initiates and/or sends the vericification codes - Quicken, Discover, a 3rd party entity? I need to get this figured out, and if nothing else, I need at the very least another verification code option - email, call, etc. I don't think that's a Discover problem and it definitely isn't a U.S. Cellular problem. Can this please be resolved?