Mail App Duplicating Inbox

As shown in the below picture, my inbox for my Work email will get, randomly, automatically duplicated by my iPhone. The red arrow is the normal inbox and the green arrow is the extra duplicate identical inbox that randomly appears.

There seems to be nothing apparent that triggers this duplicate inbox to appear. It just happens every once in awhile.

If I go to “edit” and uncheck the extra mailbox, it goes away for the time being but it will come back. Sometimes it’s the next day, sometimes days/weeks later. Also, when I uncheck it, I can’t go back to edit and “re-check” it. It’s no longer on the list of available mailboxes.

I have this same email account synced on my iPad and this never happens, so it is something exclusive to the phone

Any ideas how to fix this permanently? It’s annoying to have to remove it when it randomly shows up...