Battery Replacement quit working

Unit wasn’t booting at all - just alternating between orange and green lights on the power adapter when I pressed the power button. Based on other advice given on this site, I pulled off the shell and unplugged the battery and the unit started.

So, ordered a replacement battery and put it in. Battery appeared to be working except the unit wouldn’t boot on battery - online when plugged in. Once it was starting I could unplug the adapter and the unit would continue to run.

Based on other advice, I was running the battery down to “recalibrate” it but I was cleaning up an infection at the same time and when I rebooted from that it wouldn’t boot again.

After some troubleshooting I discovered that I am back at square one - the unit will only boot when I disconnect the battery. So now I am back where I started and am questioning whether the original battery was bad to begin with.

Anyone experienced this before? And suggestions?

I thank you in advance for any assistance.

Shawn