GFX50SII refuses complete manual focus

[AGarciaferro]

Hi! This is my first post in this forum and glad to search an answer for a (maybe) a niche quirk/issue. My GFX50SII has AF-ON button on, this means it wont focus with the shutter button, while camera is in MF Mode (with the back switch on right side on visor) if I press the AF-ON button once again, it will search for the focus where the AF-Point is. This is annoying specially for night/landscape photography. I´ve been looking that my panorama shots at night, just the middle photos (of the panorama) are defocused, maybe for the way I manipulate the camera. 

I find this annoying and start to search in the menu for AF assist menus (such as Rapid AF, Pre AF, AF+MF set off, Focus Check OFF, and any function related to this) and camera, besides be in MF Mode, it will search for focus whenever AF-ON button is pressed. 

Hope someone has experience with this issue. 

Thanks in advance. 

Alfred.