iPhone XR says it's charging but it's not, and it's stuck.

Hi peeps,

So I had a pretty damaged iPhone XR and today I finally decided to give it a fix. I work at a cellphone repair shop so i’m pretty familiar with fixing and such. Anyway, I replaced the LCD, battery, and lighting charging port because the screen was cracked, the battery was fried, and it wouldn’t charge. It booted up and worked fine until I ran into some problems. For some reason it says it’s charging, like the charging icon is next to the battery and says it’s charging yet right now its at a standstill of 2%. I tried draining the battery because I thought maybe I needed to drain it first and then recharge it, but it’s totally stuck on 2 yet it says it is charging. Does anyone have any ideas or suggestions? I would appreciate it greatly, as I am stumped on what to do and I would love it have it as a back up phone and share it with my family. I just don’t know why it won’t charge though and would love any advice. Thank you very much to all!

Thank you

-Lun