Proxied accounting

I'm currently running Freeradius 2.1.7 across 3 servers and have been having a recurring issue where proxied accounting packets stop being relayed to my customers approximately after 1 month of uptime. Auth still works just fine, but for some strange reason, acct just stops being relayed. At first, I was assuming it was a firewall problem but simply restarting radiusd fixes it. I don't have any debugging info about this unfortunately, is there a way I could use raddebug in a useful way to find where the problem is? Or am I out of luck here?