Well, switching it to AE BKT, keeping the shutter depressed while it shot 3 pictures, and then switching the DRIVE button back to FILM SIMULATION BKT fixed the issue.
My menu is apparently slightly different from the X-camera series menu. (I wish I still had my X-H2 to compare.) There is no separate DRIVE SETTING option under the SHOOTING SETTING.
But all is well that ends well. Thank you for your help!