Fn+F3+B does not bring up hitboxes

When on a device that use a Function (Fn) key to access f1, f2, f3, etc., Hitting Fn+F3+B does not bring up hit boxes. However hitting Fn+F3+G dose bring up chunk boundaries and Fn+F3+H does enable tool tips.

Attachment link:

https://drive.google.com/file/d/1c_k-MxtMLgo2rD_tmI9PowgG3uNg9Q2m/view?usp=drive_link