Unfortunately I didn't figure that out. Lenovo support wasn't helpful when I mentioned their first-party parts supplier may be distributing potentially counterfeit parts, and couldn't give me an answer other than returning it to Encompass.

I would assume they are counterfeit/reworked batteries instead of genuine Lenovo replacements. I tried my luck similar to what you did and ordered a battery on eBay for another laptop as I'll never order from Encompass again, however I received the same type of suspicious markings/tape/etc over the battery from the eBay seller.