Visual Voicemail forcing me to "Call Voicemail" on iOS 14.4 iPhone 11

I switched my carrier from Sprint to Mint Mobile, both of which support Visual Voicemail. However once I switched to Mint Mobile, my Visual Voicemail has dissapeared and voicemail tab says "Call Voicemail" in the middle. I have reset my network settings, turned airplane mode on/off, and I have done a complete factory reset of my iphone (iOS 14.4) (iPhone11). I was never prompted to set up my voicemail even after the factory reset. The "Call Voicemail" remained. I called my phone from a different number to prove calls work, and I left a Voicemail, but no voicemail populated in the voicemail tab. I called into my voicemail and the message I left was there. Mint Mobile says it is not an issue on their end as my plan supports Visual Voicemail. How do I resolve this issue?