Ipad 8 not charging after screen replacement, though port still works

Hello! I’m a bit stuck with this one:

I recently did a screen/digitizer replacement on an iPad 8. While tricky, I managed to get everything neatly reattached and reassembled. The only uncertainty I had with this repair was disconnecting the battery, the only method I found online was to slip a non-conductive card of some sort (i used a plastic sheet) in between the battery connector and battery to sever the connection (since there is no other way to disconnect it without removing the battery)

Anyway, iPad booted back up and everything worked as it should, until I went to charge it. Upon connecting a lightning cable, there is no charging indicator and the battery symbol is still red.

However:

• When turned off, plugging the ipad into a charger turns the ipad on
• When plugged into a computer, it recognizes the iPad.

Any idea as to what happened here, and how I go about fixing it? my only guess is to disassemble it again, completely remove the battery and fully separate the connection, then reassemble.

Thanks