Send to remote fail

Hi,

When sending to remote B2 storage I’ve had one site throw the same error for a few days now:
<>Error Message: Received error from B2: Not enough members for write of 4_z6a81f9990b8a50a9640a081a_f10573c3c2ca7d7bd_d20180530_m150053_c001_v0001105_t0043: class java.net.SocketException – Connection reset (http://member-08.vault:8180/api/put_shard?sguid=4_z6a81f9990b8a50a9640a081a_f10573c3c2ca7d7bd_d20180530_m150053_c001_v0001105_t0043_s08&is_first=false&is_last=false&is_speed_test=false&upload_id=87e2cc2447f1ba7d47418&shard_size=120359441&offset=66682880&reason=UPLOAD_B2);

What could be causing this? The connection to B2 validates in settings, and all my other sites backing up to the same B2 bucket work fine.

Thanks,
Ben.