Android Studio don't recognise xml file in layout

Question

I have a xml file layout ( fragment_navigation.xml ) but android studio doesn't seem to recognise it as xml.

No xml icon

No syntax highlight

I create the same layout with different filename and it works for a time after close and open the project again.

My environment is:

Android Studio 3.2.1
Build #AI-181.5540.7.32.5056338, built on October 9, 2018
JRE: 1.8.0_152-release-1136-b06 x86_64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
macOS 10.14.2

Answer 1

Ok, I saw an option right-clicking on xml file "Mark as XML" .

And it persist for next project opening.