How to use methods from Objective-C main app in Swift target?

I have an Objective-C app with a new iOS 14 Widget (a Swift target), and I want to use a few methods from an Objective-C class in my Swift target, but am having one issue with it.

The class is called SharedUtils, and the methods are marked as class methods in the .h file. I don't create instances of this class, I just use the methods.

One of the methods I want to use is:

Code Block objective-c
+ (NSString *)symbolForCategoryId:(NSNumber *)categoryId;

This works fine in the Objective-C main app, i.e.:

Code Block objective-c
[SharedUtils symbolForCategoryId:myId];

In the Swift target, I start typing:

Code Block swift
SharedUtils.symbol ...

and Xcode autocompletes to:

Code Block swift
SharedUtils.symbol(forCategoryId: NSNumber(value: myId))

If I don't set the bridging header in the widget target's build settings, or I remove the import from within the bridging-header.h file, Xcode cannot autocomplete the line, so I know that the Swift target can see the SharedUtils code. All good so far.

However, when trying to build the code, Xcode errors with:

Cannot find type 'SharedUtils' in scope

Any idea how to get this to work? I've used Objective-C code in a Swift app before and not had an issue, but the code was all in the same target, so I'm thinking it's something to do with that?