Yes, different blades from different manufacturers
do vary in thickness/size despite the same numbering.
Torsten's advice can work for you. Others will run some sandpaper along the ends of the blades to make them a little rougher, and some will wipe the ends of the blades with a little bit of mineral spirits to remove the oils left over from the manufacturing process.
Any or all of these things should help out! Good luck!
Oops, Sheila was a little faster on the trigger!