As others have said the force required to remove the freehub varies but you may not have clipped the small black ring around the freehub body back into place

Edit: Oops too slow 🙁 I will also add that you dont NEED the tool that hope recommend I usually use the back of a pencil, or a scrap of plastic, and just work my way around the seal.

Thanks for the help, I already have an ultegra cassette and it is still cutting in due to the fact that some of the gears are still loose. I may try an XT as it has been a while since I used a larger cassette and I may like it now, although this theory never worked with broccoli :(, my riding has changed since I last owned an 11-32.