Which version of NDK should we use? not latest?

I was told that we should always use the version NDK according to below
https://github.com/xamarin/xamarin-android/blob/master/build-tools/android-toolchain/android-toolchain.projitems

as it seems 14b version is used, we can use highest 14b? which is from march 2017, pretty old. why is it? I tried used 18b today latest version and my project works fine in debug mode and compiles also fine in release mode. Problem occurs when i want to install the app in release more or try to create a package. I get this exception

Error       XA5101: C compiler for target Arm was not found. Tried paths: 
"C:\Android\android-ndk-r18b\toolchains\arm-linux-androideabi-4.9\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe; 
C:\Android\android-ndk-r18b\prebuilt\windows-x86_64\bin\gcc"

So, can someone confirm from xamarin team if we can rely on android-toolchain.projitems file or we can simply use latest NDK, maybe my exception is something else?