Normalization by integrated monitor seems to be broken

[jl-wynen]

          Not completely empty for me but definitely broken:

This seems to be a problem with the integrated monitor norm. I don't know what. But iit should not have been caused by this PR.

Originally posted by @jl-wynen in #145 (comment)

[jokasimr]

Has this been fixed already? Should the issue be closed?

[jl-wynen]

It might be fixed by scipp/essreduce#252 But I still need to check