a) I have a few threads bookmarked as “Windows drivers” + “waiting for any device” – here is one, is this your issue? FP3: From 0.23 Android 9 to /e/OS 1.x - seeking clarity - #16 by aibd
b) Are you saying
I am expecting that you can engage fastboot mode from Phone off Power + Volume Up ?
… does not work ?
c) Was you phone definitely on Android R=11 before you started ?