I'm not familiar with the CAD symbol you want so this is my best guess based on your description.
It seems that circles and polygons are treated differently in how the fills are created and when or if you can use point hatching.
For your rectangle, you have selected "Smart Polygon", the circle doesn't have a "Smart" counterpart. If you had used "Single Line" for the rectangle the two objects would have behaved the same. The "Fill" tool requires a polygon to be associated with, using the "Smart Polygon" option only needs the "Show Fill" set to on and a color selected. Using the "Single Line" option to create the rectangle and then using the "Fill" tool will make a polygon and fill it just like the circle did.
Clicking inside a "Smart Polygon" with the fill tool will result in an error "No Valid Hatch Region Found". Why, the "Smart Polygon" is one object. The tool is looking for a series of curves that are closed using the end points of each curve until it gets back to the start point. Should you hold down the shift key and click on one of the "Smart Polygon" sides it will now make a second polygon and fill it. Holding the shift key allows the tool to see the line as a separate entity along with the connecting lines to form a polygon. If the tool can't find a valid hatch region then holding the shift key and clicking each curve forming the region will give you a fill if the selected curves are connected end to end.
For the CAD symbol, I made the circle and added the 5 lines then hatched two of the quadrants. Selecting the fill tool and clicking on the circle would result in a filled circle, I don't think you want that, just two filled quadrants. Using the "Segment At Location" tool I divided the circle into four arcs, set the fill color and while holding the shift key clicked on the arc and the two sides for each filled quadrant. For the background rectangle, I selected "Smart Polygon" and set the fill color. I dragged the rectangle over the symbol which hid the symbol under it. Set the polygon "Show Fill" to "No", drag a fence around the CAD symbol inside the rectangle, don't select the rectangle. In the "Arrange" menu click on "Bring To Front". Go back to the polygon and set "Show Fill" to "Yes".
The red "Stop Sign" with an R in it is telling you that the associative links are broken. Under the "Edit" menu the normally grayed out "Resolve Links" should now be active, click on it to see if it can fix these links. While in the "Entities" tab you can right-click on the name and select "Force Resolve Links".