Some hatches are visible in layout space, some are not.
If some of your hatches are annotative in nature, they will not be visible in layouts unless the viewport scale matches the annotative scale.
In my experience working with BricsCAD users, I have seen that this is often an un-intended consequence of some hatches inadvertently being marked as annotative.
To fix this issue, you can right-click on the hatch in model space, select Properties and change the “Annotative” property to “No”. Once you do that, it will show correctly in the layout space.
Alternatively, you can modify the ANNOALLVISIBLE variable from 0 to 1 and restart BricsCAD. By default, its value is 0, so only annotative objects that support the current scale representation are displayed.