I downloaded maps to system storage then remembered to change storage to SD card. I now find that I still have 4GB used in /storage/emulated/0/Android/data/com.myrouteapp.navigation/here-cache
So changing the storage location does not remove stored maps and changing back to the original storage location does not re register the existing maps even though they are still there.
My next move is to reinstall Navigation for a clean start.
In the Android Application Manager "Navigation" is listed as using 4.12 GB of data on the SD card even though the SD card only has 1.5 GB data on it in total!
On using the application manager delete all data for this app option the data was deleted even though it was listed at the wrong location.
On reloading a map it went in internal storage, next a full reinstall.
This is on a Samsung SM-T520
Reinstalled Navigation on the Samsung tablet - no change everything goes in internal storage even though and the app itself and the 'Application Manager' say its in the SD card.
Now checked my phone, also set to download maps to the SD card still downloads to internal memory.
In this case the 'Application Manager' correctly reports the memory usage as internal.
The phone is a Blackview BV8000Pro running Android 7.0
After a recent update the maps are correctly stored on internal memory or SD card as set in the options. This does not tidy up any incorrectly stored maps from before the change. I suspect manually deleting files may break things.
The best way would be to go into Android setting | App management, select Navigation and 'delete all data'. This will give a clean start. You will need to re enter your registration details and download all required maps.
Thank you for the suggestion, I tried clearing both cache and data via App management but the 1.5GB was still showing in the here-cache. The storage details for the app showed 0 bytes cache and 0 bytes User Data.
I manually deleted the contents of the here-cache folder then downloaded the offline maps again and it does not appear to have any adverse affect on the app.