I bought a Pro-16 a few weeks ago. It keeps hanging several times a day. It is on Ethernet connection (I am not using wifi and most discussions I found were about wifi).  When it freezes, it cannot be accessed from the app nor a web browser. In most cases, it is possible to SSH into the device and reboot it remotely, but today SSH did not work. I had to power cycle the device.

The firmware version is 4.0.1152

Please help. It is a great device but does not work reliably for me. 

I tried to set log level to "DEBUG", but it does not work - it keeps returning to "NORMAL" level.

UPDATE: I have contacted product support. They are going to send a replacement device. This will confirm if this is a hardware problem.