EY wrote on Apr 5^th, 2021 at 3:03pm:

To arm approach (first 3 steps in any order)    1. Set both NAV radio course    2. Set both NAV radio frequency    3. Switch both NAV radios to manual    4. Push Approach (APP) switch    5. Verify Approach is armed After Approach is armed:    6. Select CMD on Second A/P

I did all that but it didn't work. It just switched from A to B. I tried several times once at like 1400 ft. Didn't work at all.