Starting in 8.1.2 Ignition’s QualityCode system gained a Good_Overload code that is now mapped to when a Good_Overload StatusCode is received from an OPC UA server.
You were likely always receiving this StatusCode on value changes from this server but previously it was just ignored.
Slow down your sampling rate (Tag Group rate in Ignition) or just ignore it. The QualityCode is purely informative, it doesn’t have any representation in the tag browser or the quality overlay system.