Boot loop after swollen battery replacement, 4013 error

Phone: iPhone 6

Cable: genuine Apple cable

Charge brick: genuine Apple

Swollen Battery: iFixit battery, less than a year old

Replacement Battery: iFixit battery

I realize this issue is documented and answered in places. but felt my situation does not perfectly match those, and needed more answers.

What happened: I started noticing the battery swelling and pushing the screen up about 4 weeks ago, mid December 2018. The phone was crashing when it wanted. What I found to stabilize it was having it plugged into an Anker power block at all times. Needing my phone for, well, everything, I ordered the replacement battery, and kept it plugged into the Anker for stability. The phone was actually working and stable with the Anker life support system it was on.

I received the replacement battery, performed the surgery according to instructions. I have moderate expertise with small electronics, been fixing them off and on for years.

When I went to power the phone up, it was stuck in an endless boot loop of the Apple logo. I need to get into the phone pretty badly for data on it, data that was fresh from the last backup - holiday pictures, notes, etc.

Went back to the swollen battery, with Anker, same thing.

So, I got it to go to recovery mode, hoping to do the update option, so that the data would be preserved. When I plug it into iTunes, it gets ready to engage the phone, but the phone just enters the boot loop over and over and won’t allow the update. or anything else.

Any insights and help are much appreciated.

Eric