does macOS High Sierra work with fusion drive?

I'm curious as to what problem you are having as well. I've been running High Sierra since June on iMacs with Fusion drives. Mine seem fine.

I never reformatted my drives. I went straight from Sierra to High Sierra. Whatever issue you had had nothing to do with High Sierra on Fusion drives.

I am really lost then as it did it twice on an old fusion drive and then again on the new one that apple care had installed on my machine to fix what they thought was a bad hard drive.

Without all the details of exactly what happened it's impossible to say. But many people are running High Sierra on Fusion drives. Just without APFS.

How do you run it without one of the main benefits of High Sierra. I see no where during installation to tell it not to use APFS.

First, APFS is a benefit to SSDs. Second, it's not mentioned because it won't convert a Fusion drive to APFS.

You're welcome. There's a lot of details I'm sure that are missing. I can't speak to what was done or why. I can say I have had no problems with High Sierra on Fusion drives nor have most people.