Side door latch/lock won't close without assist...

When you want something to go in more easily, lubrication is your friend.

Try putting lubricant, even just bearing grease (to test) on that face area circled in second pic. Also wipe just a little on the strike plate.

If that fixes the problem, then use a lube that is more suited, as to not get on clothing or attract dirt. I use just a light film of teflon trailer ball lubricant.

Jerry