GFX50S lens attaching problem

[Styxoncamera]

I have just purchased a brand new GFX50S Mk1 body. Also bought separately I have the new GF35-70 lens. 
when trying to fit the lens onto the body, I am getting resistance and it needs a lot more effort than it should to attach the lens. 
is this a general problem or something new?  
 

[Herco]

It's difficult to determine how much effort you feel is 'a lot more...', but in general this should not require much force at all. Read Attaching a Lens (fujifilm-dsc.com) to make sure you've aligned the lens correctly and make sure the lens mount rests flat against the camera mount before you turn it clockwise (viewing from the front of the camera). If it still requires effort and/or you don't feel it click in, go and see a Fuji dealer. It might be a mechanical issue. Whatever you do, don't force it. Mount repairs are generally expensive.

[Giampaolo Masserano]

When I used Leica reflex (film), a technician suggested a very light lubrication using (with extreme caution) a cotton swab with a single drop of lubricant and then wiping with a paper towel to distribute it better, eliminating any drop even the smallest.

With the digital sensor so exposed, you have to be even more cautious.

I also had the same problem with the GF35-70, but after some assembly / disassembly the necessary force decreased. The new "bayonet" must also be "run in" due to the presence of the rubber seal ring