About a week after updating to firmware v1.3.6 I noticed that none of my cameras were recording anything anymore. I tried restarting the hub, after which it told me that my SD card had some kind of size issue (can't remember what) so I tried to format it but it returned an error and didn't let me. Tried again - same thing. Restarted the hub again, then it let me format the card and then everything started working normally again! All cameras recording normally.

So, in case I'm not alone here, if you update to v1.3.6 I'd suggest:

1. Check that your cameras are still actually recording, if not
2. Try to format your card (noting you'll lose all data), and if it doesn't let you,
3. Restart your hub and try to format again.

Hope this is of some help to someone - I was fumbling around for a while!

Cheers.