Settings default to Metric; unable to change (and keep) to Standard.

[A Former User]

Location = United States
Device 1 = Kindle Fire HD 8 (7th generation) -- Even though my settings reflect my preference of Standard measurements, the display still shows Metric.
Device 2 = Lenovo ThinkPad, Windows 7 Pro, Chrome Browser (version 71.0.3578.80 (Official Build; 64-bit)
Please help!