Two phones, two batteries. Won't hold charge?

Greetings!

So I had two identical phones I wanted to replace both charging ports and batteries. Now that both replacements are complete neither will accept a charge? Both batteries had about 20% charge when I plugged them in for calibration. Lightning bolt showed they should be charging however the phone screen said charged? I watched both phones on good chargers dwindle down until they shut off. Next day they won’t turn on and I cannot find anything online about this issue. Might anyone have some insight into what may be happening?

Thank you in advance!