Sounds like you are doing really well
@Ruth W
It’s not uncommon for the first reading of the day to be the last to come down, and some people find it can be quite stubborn.
How long have you been getting those single figure readings during the day?
What are your last readings of the day like? Do you check at bedtime?
If you are curious you might want to take a few bedtime checks, and also set an alarm for 2am or 3am to see how things go overnight for a few days. That is typically around the time when the body’s cortisol release is at its lowest. It would also help you see whether your liver is dumping glucose in the early hours (dawn phenomenon)