What are your buffers set to? I find 1200 on the RTCM and 250 on voter.conf works well in most circumstances.
If rebooting fixes the problem for weeks then sure, reboot the node periodically.
I heard of this once, RTCM Network Issue but I don’t think that’s the problem you are having.
Also are you using the terms “voter board” and RTCM interchangeably or do you have a mixture?