7.7.0 - SQLTags$ClientSubscriptionProxy Error

We are having some problems on a redundant pair of servers. Many of our issues have known causes, but I logged on today and found a log full of this message:

3:55:45 PM 	SQLTags$ClientSubscriptionProxy 	Client subscription proxy got a tag change event after it was shut down.

This was being logged several times per second and had been going on for at least several hours. Based on other posts I restarted the Gateway which did stop the messages.

I never saw a clear cause listed in other posts. Is there something I need to be aware of to prevent this in the future?

Really strange. We have exactly the same problem.
Running 7.7.2 here.
Started this morning… I don’t know the exact time because we have more then 4000 of these messages.

After restarting the gateway it has been fixed. But it would be great if we know how this occured.