Would seem straightforward to have a short sentence on unlocking doors and liftgate. You CAN do it with the fob IF the car is turned off. You CAN do it with the side switch IF the car is turned on. You're saying this is in the "operators manual"? Don't think I ever saw one of those, and I've never seen an online link to one. The manual is mostly about safety. car companies protect themselves in that way. Can't say we didn't tell you that ... they can say.

 

Actually, it is pretty straight forward if you read it.
Owners should be able to extrapolate that "Transmitter" is the FOB.
If they can't not sure I'd want them driving
The owner's manual can be found online here is the link.
2025 Mazda CX-5 Owner's Manual | Mazda USA
Do a search for liftgate and you will find this

• When the ignition is switched ON, the transmitter does not operate.
  
  Opening the liftgate
  
  If the vehicle has satisfied all the following operation conditions, the power liftgate can be opened using the power function.
  
• All doors and the liftgate are unlocked.
  
• The ignition is switched OFF, or the selector lever is in P with the ignition switched ON.
  
  Yeah, the manual is a long read but then so were my molecular biology textbooks.
  Just winging in it rarely works
  

 

Actually, the wording is pretty obtuse. Maybe a Japanese/English issue? "All doors and the liftgate are unlocked" but it doesn't specify how to unlock. Easy enough to write that the interior unlock button must be used if the vehicle is on, but the transmitter can be used if the car is off. There is also the lock/unlock button on the underside of the tailgate, but I don't know if this would work with the car on and gear selector in park.

 

Quote: "There is also the lock/unlock button on the underside of the tailgate, but I don't know if this would work with the car on and gear selector in park."

It tells you it does in reply I sent.
If the vehicle has satisfied all the following operation conditions, the power liftgate can be opened using the power function.
The ignition is switched OFF, or the selector lever is in P with the ignition switched ON.
Power function refers to any button that operates the liftgate.

It would seem you may have some reading or comprehension issues...
Or possible just an aversion to reading instructions.
Anyway, now you know how it works so hopefully that resolves it.