Same problem here. Meter would indicate that it already had the latest FW version but would always download it over and over. Additionally, I could never Set the device name. And occasionally the Logging:OFF / Logging: ON toggle would not toggle. And occasionally the SD card would report that an error had occurred. The battery voltage was below 50%
So, tried different SDHD card (32GB, extended FAT32 format under Windows 10 in Parallels window on iMAC). Removed batteries, waited, pressed reset button (?), and installed new batteries. Seems to work properly now.
I’m assuming that being able to email your SD logs from an iPhone 6S, latest iOS, depends on having the beta app? From the metering page the logging ON/OFF button never goes to any other page.