After replacing the battery with an IFIXIT battery it won't charge

I replaced the battery - all went fine. Phone came on with about 20% battery so tested all the functionality of the phone no problems. I used it until it went below the 10% as specified and then put the charger on it. Got the noise and icon indicating the charger was attached, but it's not taking a charge. I shut the phone off and rebooted, but still just sitting there at 16%. Been charging for over an hour.

Any ideas on what the issue could be?

Sorry - I should have included more. The phone is about 3 years old and the reason for replacing it is because it would only hold a charge for an hour or so. Also, I have used a Mophie case, otherwise I use the charger that came with it. I have tried switching the charger and cable with my wife's iPhone charger as well.

Would the lightening port allow the phone to acknowledge that it is plugged into the charger and charging as the tone and icon on the home screen show? I would think if the lightening port were bad it wouldn't show that.

I suppose that would be the next thing to change.

Alright, now I have a bit more to comment on. After a number of hours the charge is up to 54% and it seems it only takes a charge if I am using it. Does this make any sense? If I stop it stops showing the charge % increasing, but if I use it actively I can see the charge % go up slowly. I'm baffled.

One more clarification - I have found that I don't need to be using it for the charge % to increase, just turned the autolock off so that the screen stays illuminated all the time. The charge % continues to increase. I remain baffled.