We've got a CCR1009 at the interface between our network and the backhaul provider.
Backhaul is a 300Mbps symmetrical on a 1 Gbps carrier. Our network typically runs with the load at 50-100MBps download with peaks to around 200MBps

It's been in service for about 6 months. Performance is generally OK, but a few months ago it started to freeze - traffic through the CCR throttled down to almost nothing.
During the freeze, Winbox will connect to the CCR but none of the windows populate - just blank.
We can still ping through the CCR to the outside world, but can't open web pages or send any traffic.

We've been working with our backhaul provider and they have ruled out DoS.

Any ideas?
We have 80 customers on our network and their patience is running out.

What firmware you running? do you have a public IP facing the outside world. post config.