Using the smart key doesn't allow me to open the trunk plus the button by the steering wheel. Could it be an electrical problem? My dashboard indicates that the trunk is open, which isn't the case.
Any pointers on how to approach this situation? Any help is very appreciated.

 

Probably your key is from the different jaguar xf

 

Could be the wire broken that goes from body to boot with flexing

 

There is a mechanical key slot under a black plastic cover underneath the boot lid plinth. The mechanical key is inside the fob.

Your issue, if neither the fob nor the dashboard switch work, is failure at the trunk solenoid right at the latch. Probably the warning message is related to this failure.

 

Thanks everyone for the valuable information.
As a result, I'll be taking the vehicle in to the dealership.
I'll also repost here of the results that I receive from the mechanics to help everyone in the forums of similar trunk issues.