Subscription Manager issue with Scanclass?

I have 2 scanclasses dedicated to reading data from an OPC connection using a driver we built in-house. Unfortunately, the person who built the driver is no longer with the company, and left no documentation we can find concerning how she did her work.

We seem to constantly have errors like this:
"10:32:20 AM SubscriptionManager Error adding 11 nodes to subscription ‘Scanclass ‘Flexsort Historical[default]’’ @ 15 seconds.

StatusCode[Severity=Bad, Subcode=Bad_Timeout]: Request timed out after 120000 milliseconds.

I am assuming that this means that the issue is being caused by the fact that the scanclass “Flexsort Historical” contains data/tag information that is not updating in the time period defined inside the scanclass, and is the cause of “Subcode=Bad_Timeout”.

If this is the case, then is there something I can do about this?
Do I need to adjust our driver’s sourcecode to have it periodically force a tag to refresh to get this issue to go away?

I can provide additional information if needed, but am wondering if this is simply the system’s way of saying it just needs some new data in order to keep the connection from going stale in the OPC server

It’s hard to say what’s going on from just those two log entries.

My initial guess, assuming the entries are related, would be that the driver is not responding to a call in some way and that is causing a request to create monitored items to time out.