DirectAccess Troubleshooting - Hit and miss results depending on location

Hello!

I've deployed DirectAccess (Windows 2012 R2) out to quite a few laptops all using Windows 10 Enterprise.  Generally it works really well.  However, in certain locations such as hotels, coffee shops etc it appears to be stuck on "Connecting", sometimes it even says "Connected" but doesn't work.

We seem to struggle more overseas (we're UK based, but we have staff in the US).

I wanted to start up this discussion to see if anybody else has these problems and also what troubleshooting steps are available.

Thanks

M