Interesting, I've not had that issue. I'm just adding E98 to the fuel tank of cars and run them for 10 minutes or so while watching the fuel composition sensor.

Once mixed the composition sensor would read the same alcohol content, even on an overnight cold start/drive it stays consistent.

69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700