The problem occurred before midnight, as you can see on the graph, so I don’t think that is related.
Initially, I was reminded of past problems that I had also had with having the GlassWire window open at midnight:
The other time that GlassWire stopped logging data was on an earlier test version, 1.2.57b. The only common thread I have noticed is that the data logging stops after I spend a couple of hours working in the GlassWire window. But it doesn’t stop while I am actually viewing GlassWire: