Help Needed: INSV Remains Spherical Instead Of Equirectangular

As I understand, the app or the Insta 360 Studio should automatically convert the 2 fisheye recordings from front and back lenses and stitch them into one equirectangular video - which is the case for all of my footages taken so far, save for 1 key footage which remains as a fisheye orientation even when I try opening it in the mobile app or in the Insta360 Studio.

In fact, when I open the INSV file in Insta360 Studio, there are no options on the right under the Stitching Panel.

How do I get an equirectangular footage out of the 2 fisheye footages I have now?