Tuning FX Wildcat MK3 Fill Probe is Hard to Insert in Gun

Ever since I got the wildcat it has been very hard to slide the probe in the fill port on the gun. I have to push the probe in hard and push in the opposite direction on the cylinder so I can get it in. Lately it has gotten worse and now I’m seeing premature wear on the probes o-rings. I just watch a video of a guy one handing the fill process on his wildcat. That would be impossible with mine. Nothing looks to be obstructing it and the port looks clean. What are some options/opinions/tips? Is there anything I can put on the probes o-rings to make it slide better without contaminating my air cylinder? Thanks. 
 
Purchasing the stainless steel HUMA probes fixed all my probe issues with problem fill guns of several different manufacturers especially when replacing the factory brass probes.

X2. I replaced a brass fill probe on my TaiPan with steel from Donny FL and cant believe how easy it slides in now. His came real fast too. I ordered a spare from Huma but it’s still in transit.