Constant "Work stale due to work update"

[patrickgardella]

I'm running bfminer 5.4.2 on an Ubuntu 16.04 x64 computer with a Gridseed 5-chip ASIC.

Log file can be viewed here.

Every so often, the bfgminer stops sending work back to the pool. From that point on, it constantly reports "Work stale due to work update" or "Work stale due to block mismatch". It's almost like it gets behind, and can't catch up. Once I restart it, it works fine for a random period of time, usually hours.

This doesn't happen everytime I get the "Work stale due to work update". As you can see in the Gist, it throws that debug warning on line 280. But then at [2017-08-01 11:30:53], there is the last Accepted line. From that point on, it doesn't submit anything.

So my questions are:

1. Any reason why this might be the case?
2. How I can get it to submit the stale work anyway? stale timeouts are set to the defaults.