Why does Apps storage show internal storage when using an SD Card

[Android Central Question]

My phone is telling me it is running low on Internal storage. It is showing Amazon Music as using 1.49GB, but then when I go to the details of Amazon Music, it should Storage Used is SD Card. Data is 1.46 GB and App is 30.50 MB. I am guessing that the system thinks that 1.49 GB is being used internally, when it is not, and therefore giving me the warning. How do I check if that is so and/or fix this? I have a LG K20V (VS501), running Android 7.0.