upright Greek letters (like `\upmu` from upgreek latex package)

[thearia0]

On the screenshot, the mu letter typeset with ylabel="Radius "*L" [\mathrm{\mu m}]" is rendered with italic font. Is there a way to keep mu upright?

[BeastyBlacksmith]

Is this using the default GR backend?

[t-bltg]

If you can reproduce this issue with plain GR commands, please report the issue in GR.jl instead. Thanks.