@josh It stopped at 12:07am this morning. No error since. I started writing the logs to my Synology syslog server and I took a look at what was happening around this time - nothing out of the ordinary.
Although I was happy to see all of my touchscreens updating as expected this morning, it does leave me with a certain sense of fear - not knowing why or what happened. But sometimes you just have to go with the flow.
Nothing back from Hubitat yet so will leave that open to see if they can put their finger on it. Will keep you posted.