O-ring help!

My Air Arms 200T uses a BSA fill probe that was supplied with my Great White tank setup from Joe B. It worked perfectly for quite a lot of fills (200 maybe) but then a leak developed at the probe when filling.

Home Depot had o-rings that look the same but don't stop the leak. They are: Danko #36- 5/16"OD x 3/16"ID x 1/16".

What am I doing wrong? The new o-rings look just like the old ones to me. Is any lubrication recommended on the o-rings (I have some 100% silicone grease for example) or should they be completely 'dry'.

I will greatly appreciate any tips or guidance on how to get my probe to seal properly.

Thanks,

Matt