Confused about rising overnight blood sugar

I am T2, originally diagnosed over 15 years ago, but only on meds (insulin and janumet) for 3 years (prescribed to lower my levels for surgery!). My daily readings are on the high side - last 7 fasting (before breakfast) have been 9.9, 11.6, 11.5, 10.4, 11.4, 11.4, 11.7 (11-12 is my usual "fasting" range, and my daytime range between 10 and 13). What concerns me - not stressed out or anything - is how/why the morning reading can be higher than last thing at night. I know about the Dawn Phenomenon, but yesterday my pre-dinner reading was 12.3 (around 18.30pm), I took my insulin at 20.00, and then tested before bed (around 23.00) and it was 11.6 - 9 hours later (with no food intake) it was 11.7?? It is, thankfully, rare for my morning reading to be higher than bedtime, but I would have expected it to be much lower with minimum 8 hours "fasting".
At a diabetic review a couple of years ago I was told not to get too worried if my range was between 13 and 18 (I know these are on the high side, but as far as I know I do not have any other issues, and rarely go above 13), but my last review in March my "target" was single figures. I am due a follow-up (was told they would send me an appointment end of July!), and don't appear to have any "complications", and feel healthy enough.