Iphone connectors can be finicky. Go slowly and try repositioning before pushing gently with your spudger.
If that doesn’t work, look at the connector pins inside the connector / on the other side of the connection. If any of them are laying down, you have bent them. You can use your spudger to bend them back, but the pins may be damaged beyond repair in some instances. I’ve done this with the digitizer assembly in an iPhone 5, and it’s really frustrating.
Good luck - be gentle. Positioning is important and it will click with gentle pressure if you’re positioned right.