Hi Diego,
See the two Screens below. There is one FWP and theme both are selected default.
And I checked the Ajax page configuration, it's in the list. did one change SAVED it.
Desktop and AFP added below.
I added Default page template(with reference Classic FWP) but still it's showing blank.
While applying to user In master rule collection is require to do any settings instead of existing one. I used Existing master rule collection!!!
Still showing Blank for user!!!!
Thanks
Nageswara