A little guidance, if you please (Beeman R9 troubles)

Hey gang, I could use some help if you have the time. Last year I traded into a new Beeman R9. It hadn’t been shot but a few times. I tested it out and was satisfied with the quality and description of the gun, put it in the gun case and there it sat until recently. I have a family reunion coming up and I wanted something for the older kids to shoot with. I figured to have it broke in and on target to give them a chance at success. Being “city kids” they really don’t know the joys of the shooting sports. 

I have now begun to shoot it more and was running it across the chrony to check for consistency with different pellet head sizes when it acted up on me. It had been shooting the .177 JSB 8.4 grain pellets at 798 fps or just under 12 ftlbs. This being an American purchased gun, I thought it should be a little faster from what I have read and seen about them. All the different weights and brands of pellets were shooting at that 11.8 ft lb range. Then around shot 60 (by my count, who knows really how many the original owner shot) it dieseled and shot the 10.3 grain JSB over 1100 fps. After that, the energy levels kept climbing and it now shoots the 8.4 grains at 898 fps, it gained 100 fps. 

The problem that I now have is that I can not cock the gun without fiddling with the safety, pulling the trigger and then cocking it. It self engages the safety after I fire it and before I cock it. Does anyone know why this would be? I figured the speed increase must just be it breaking in and getting settled but did the dieseling break something in my safety catch? Any help on this would be greatly appreciated, thanks for your time and input. 
 
You probably have a problem with your trigger, may need some lube. The trigger activates the safety. Pull the stock knock out the two pins that hold the trigger in place and see if there is a problem there. You don’t need a spring compressor to do it. However, the pins have to go back in their original spots as one is shorter than the other.
 
Thanks for your input guys. I have a V-mach 12 ft lb kit that I bought to put in a different gun that I used to have. I guess now is as good a time as any to install it. I stripped it down and have yet to see anything out of the ordinary but I do see a TON of lube everywhere. There are globs of it on all the trigger sears, the spring is very lubed and there was so much on the seal that it is any wonder why all the shots weren’t dieseling. It took a whole paper towel just to clean off the seal. It would take a long time to burn off all that through normal shooting. I guess they must get paid by the tub of grease there at the factory! I hope to deburr it and get it back together soon. Thanks again, I’ll check the trigger block a little more when I get back to it.