Mail Signatures Not Showing Up In New Message Window

I had to delete and rebuild my signature for one of my accounts, and despite having it selected as the preferred signature in my preferences as well as having the other two signatures I use available in the account preferences it does not populate in a new message window. It, nor the other signatures, are also not available to select when I'm sending from this account.

I just updated my OS to Big Sur 11.3.1 so I'm not sure if that has anything to do with this. I've never had this issue before. The signatures available in the other two accounts function properly. I have also tried deleting and re-setting up the g-suite account as well as closing the application and restarting my MacBook.

Any suggestions on how to get my mail to function properly?