If that is a Basic Wall, then the fill comes from the assigned Building Material. Create or edit a Building Material that has a dashed hatch for its Cut Fill. The US template includes a Hatch-Dashed fill that could be used or modified for this.
David
David Maudlin / Architect www.davidmaudlin.com Digital Architecture AC29 USA Perpetual • Mac mini M4 Pro OSX15 | 64 gb ram • MacBook Pro M3 Pro | 36 gb ram OSX14