I bought my first M&P (full size 9mm) Wed night and decided to clean/lube it before shooting. When I was finished and went to put the slide back on I could not get it to come all the way back into position. It kept feeling like it was hitting something. I checked the lever that you rotate to get the slide off and it was down. I ended up having to use the disassembly tool to reach through the back cover of the slide and push the hump on the trigger bar slightly to the left to get the slide to go on. Is this normal?