Dual frequency GNSS is a killer app for mapping and marine charting applications running under Android. Please enable this on the Tab S6 as soon as possible. As noted, the Snapdragon 855 chip under Android 9 supports this. If you enable it on the S6, I'll buy two!
hope this helps,
try enabling full GNSS constellation tracking under developers option (if existent)
to enable dev option | settings → about tablet → software info → tap build number 7 times
go back to settings after then enter dev mode 😉