If MudTable operates independently, the horizontal scrollbar is only used within the table content, and the page’s horizontal layout remains normal. However, if a MudMenu wraps around MudTable (for example, to create a context menu, etc.), the MudMenu will cause MudTable to break the horizontal layout of the page. The identifying characteristic is that the horizontal scrollbar now applies to the entire page, not just the table anymore.
After spending some time investigating (by checking each property of the table using F12 – sorry, I’m quite new and just starting with MudBlazor), I found out that the problem is that MudMenu is defined as inline-flex by default. So, by adding Class=”d-block” to redefine it as a block, everything works correctly again.