No battery detected or charging light after installing new battery

I recently replaced my MSI laptop battery, which had only 33.5 Wh capacity left out of its originally rated 80.25 Wh, with a new battery from iFixit. However, when I installed the new battery Windows tells me "No battery detected" and the charging indicator light on the front of the laptop doesn't light up. As far as I can tell, the connector is the same as my old battery and is seated correctly, and when I reinstalled the old battery my laptop recognized it perfectly fine. Does anyone have any tips on what might be going wrong? Thank you!

Reading forums online, I've tried removing the AC adapter and holding the power button for 30 seconds, holding the EC reset switch for 30 seconds, and uninstalling the Device Manager driver for "Microsoft ACPI Compliant Control Method Battery" before restarting. Nothing seems to work, and I'm hoping there's an easy fix someone knows rather than me just getting a dud battery that had sat on the warehouse shelf for too long. If it's worth anything, using a voltmeter my new battery voltage is ~14.9V out of its rated 15.2V, while my old battery was outputting 17V (although out of a rated 15.2V).