Change ColumnHints
MODIFY
WalletWasabi.Fluent/Views/Wallets/WalletView.axaml
WalletWasabi.Fluent/Views/Wallets/WalletView.axaml
ItemHeight="150"
WidthSource="{Binding #ScrollViewer.Bounds.Width}"
AspectRatio="NaN"
- ColumnHints="1, 3, 3"
+ ColumnHints="3, 3, 3"
WidthTriggers="300, 660, 990" />
</ItemsRepeater.Layout>
</ItemsRepeater>

Change ColumnHints