N/A Nova Freedom, WHY the pump locks?

Hi folks,
Have read a number of posts here & other locations about the pump locking.
WHY does it happen?
I thought I was lubing well. Could it be I put too many drops in it?

Or, just design and maybe materials not strong enough for the job?

I really like the rifle. Cheapie .22 that is accurate & no tanks, compressors or pumps needed. Not much of a worry if I nick or ding the stock. A good user in the field and no real worries carrying in the pickup or if I bump the stock going through a barbed wire fence.

I just want it to work - so..., who where would I have it serviced where they beef up the pumping action so this doesn't happen again? (assuming I take care of it)