Disco 1 latch issue

[shmoo235]

Hello all, just purchased a '98 Disco had some issues that I am currently attending to. One of the big ones was rear gate and driver door latches were not functioning from the outside. Took all apart, removed latches and on both determined small "return"(?) spring broken. Purchased new latches, gate latch perfect all's well, driver door latch installed great, open/close/open/close all good until I lock the door with the key no handle opening inside or out. Force open w/screwdriver. Once forced, open/close/open/close inside and out all good lock with key nothing. I have been over the old lock with a magnifying glass trying to find what's up and have yet to figure it out. Tough to get a good look at latch under operation due to location. Checked latch strike alignment, good, binding mechanicals on the lock, nothing. Strike snaps open using inside handle and out with door open. Can't lock it with door open so can't see whats different. Making me a little nuts. Removing the latch is my last resort as it is a pain in the caboose to get it out. Any ideas would be very much appreciated.