Is isomath clashing with siunitx? If so, how to resolve italics vs upright in units?

Question

I'm using both the siunitx and isomath packages. I'm not sure whether there's a clash between those packages when it comes to Greek symbols in units. Indeed, isomath italicize capital Greek symbols (as it should to stay ISO-80000-2 compliant), while units should be upright. Therefore the ohm symbol Omega appears italicized when using \si{\ohm} while it should be upright; am I wrong? If not, how could I fix this issue? I.e. I'd like Omega to appear italicized when it's not used via siunitx, but I want it to be upright when using siunitx.

Edit: By creating a minimal example I realized that it isn't a clash between isomath and siunitx but cmbright and siunitx (I think!). Here's the example:

\documentclass[a4paper, 11pt]{article}
\usepackage{amsmath}
\renewcommand{\familydefault}{\sfdefault} % Sans serif font type.
\usepackage[margin = 2.6cm]{geometry}
\usepackage{siunitx}
\usepackage{isomath}
\usepackage{cmbright}

%%% fonts
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern} 
%%%

\begin{document}

Here I expect an upright Greek letter: \si{\ohm}. However it is italicized.

Here I expect an italicized Greek letter: $\Omega$. Right now, it works fine.

\end{document}

If I remove the line invoking cmbright, I get the behavior that I expect. But I do need that package. I use it so that the math fonts are sans serif and similar to my text fonts.

Answer 1

Load isomath after cmbright. Sometimes, package loading order makes a difference, especially when fonts are involved.

\documentclass[a4paper, 11pt]{article}
\usepackage{amsmath}
\renewcommand{\familydefault}{\sfdefault} % Sans serif font type.
\usepackage[margin = 2.6cm]{geometry}
\usepackage{siunitx}
\usepackage{cmbright}
\usepackage{isomath}

%%% fonts
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern} 
%%%

\begin{document}

Here I expect an upright Greek letter: \si{\ohm}. However it is italicized.

Here I expect an italicized Greek letter: $\Omega$. Right now, it works fine.

\end{document}

As I commented , however, the cmbright seems to be wiped out by the later loading of lmodern. One might, thus, have meant it this way. In either case, though, the isomath should be loaded later than cmbright.

\documentclass[a4paper, 11pt]{article}
%%% fonts
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern} 
%%%
\usepackage{amsmath}
\renewcommand{\familydefault}{\sfdefault} % Sans serif font type.
\usepackage[margin = 2.6cm]{geometry}
\usepackage{siunitx}
\usepackage{cmbright}
\usepackage{isomath}


\begin{document}

Here I expect an upright Greek letter: \si{\ohm}. However it is italicized.

Here I expect an italicized Greek letter: $\Omega$. Right now, it works fine.


\end{document}