Door not locking Options

[partwerks]

When holding the flap on the DS door to try and get it to stay locked, the door just bounces back. With the panel off the latch on the back/end of the door is nice and clean, and I lubricated it, but didn't seem to help any, or am I addressing the wrong problem?

I can get it to lock with the key from the outside, but I thought when using the lock button from the inside, and closing the door from the outside, as long as you hold the flap, it was to lock that way also?

One other thing, with the door open, if I use the key turn right, and watch the tab by the interior door handle, it pulls it in further, and so when I remove the key, and hold the flap, it will lock, but if I just push that tab by the interior door handle, it won't lock that way, and it appears that just pushing the tab, it is not pushing it far enough to lock.