I have the mic hooked up to a Scarlett Solo and just as of recently my vocals are so muffled to how it sounded just a few months prior. I haven't recorded in a while and when I decided to start recording again, I ran into this problem. I thought something happened with the initial mic that I owned and I couldn't figure it out because maybe it was broken, so I just ordered a new one. But the same problem is happening. I tried changing the switches around on the mic itself. Tried moving the dials on the Scarlett and I even tested recording standing in different positions. But nothing seems to give. This a brand new mic too so the mic can't be the issue.
My immediate thought was that you have the mic backwards. It is an extremely common mistake and this is a perfect description of what it sounds like when you have it backwards. If you are not sure there are a few ways to find out. One way would be to hold a flashlight up to the mic and look into the mesh of the mic itself and see if you can make out the diaphragm of the mic. It will be a big circular part that acts as the eardrum of the microphone. It’s really the only part inside your mic. Think of an ice cream cone. You would want the point of the cone pointed away from you and the bigger circle of the cone pointed at you. Also you can always do a test run and try recoding with it both ways and see if it makes a difference. I almost guarantee this is your problem. If that doesn’t fix it, try a different recording program. If you still are having the same problem, come back here and post exact makes and models of your interface, your mic, the cord used to plug up the mic, the program or DAW you are using and computer make and model and current operating system (e Capitan, Big Sur?).
Good luck with your problem. Just be patient and focus on solutions and gaining knowledge. Every problem is an opportunity to learn something.