Hello Thomas
I’m using a swedish keybord, and I get the slash with the one I’ve highlighted, in both Band in a Box and RealBand.

It's in the lowercase position so shift is not required.

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scandanavian keyboard.JPG (44.12 KB, 86 downloads)

Band in a Box & Real Band 2023 (latest build)
Windows 11 Home - Intel Core i7-8750H - 2.20 GHz - RAM: 32 GB
Steinberg UR-RT4