I've had similar experiences with other institutions. The explanation boiled down to KYC policies and some relationship to newer DHS Real ID regulations.
So, what used to be allowed, is no longer. This might be true everywhere.
While I thought that might be the case, I got a credit card after this with my middle and last name. AFAIK, as long as the bank has both your true legal name on file and your preferred name on file, the card can be issued in your preferred name.
for whatever reason different names on credit cards slip through the regulatory cracks but the name linked to a bank account will not. the AML/KYC process is more regulated. frankly i think you are being a bit unreasonable given it's not like you actually changed your first name.
I've had similar experiences with other institutions. The explanation boiled down to KYC policies and some relationship to newer DHS Real ID regulations.
So, what used to be allowed, is no longer. This might be true everywhere.