Why is my new battery behaving weirdly?
Nothing at all looks odd or out of place. Each of those measurements shows the battery is very good and reporting new cycles. 

The circuitry that measures this is desiged to capture long time periods so I wouldn’t check back until the battery has 25, 50 and 100 charge cycles. The estimates are derived as time series of voltage measurements that are integrated, so external temperature, CPU / GPU have a large impact in adding noise to the measurements.

Averaging all of the measurements made so soon seems prudent. Unless and until you’re at 80% FCC - these won’t really tell any compelling story in my experience.

If you have a dramatic failure outside the normal aging process, that also is so clear and logged to different diagnostic logs - trying to read these tea leaves of 1% either way isn’t going to tell you anything about the condition of your device.