Unexpected value of the `normalizedNames` header provided. Expecting either a string, a number or an array, but got: `[object Map]`.

The headers object is:

{
  "normalizedNames": {},
  "lazyUpdate": [
    {
      "name": "Authorization",
      "value": "Bearer <token>",
      "op": "s"
    }
  ],
  "headers": {},
  "lazyInit": {
    "normalizedNames": {},
    "lazyUpdate": null
  }
}

Angular CLI: 18.2.8
Node: 18.20.4
Package Manager: npm 10.7.0
OS: linux x64

Angular: 18.2.8
... animations, cli, common, compiler, compiler-cli, core, forms
... google-maps, localize, platform-browser
... platform-browser-dynamic, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1802.8
@angular-devkit/build-angular   18.2.8
@angular-devkit/core            18.2.8
@angular-devkit/schematics      18.2.8
@schematics/angular             18.2.8
rxjs                            7.5.7
typescript                      5.5.4
zone.js                         0.14.10

@Injectable()
export class AuthInterceptor implements HttpInterceptor {
	constructor(private authService: AuthenticationService) { }

	intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
		return from(this.handle(req, next));
	}

	private async handle(req: HttpRequest<any>, next: HttpHandler): Promise<HttpEvent<any>> {
		if (req.url.startsWith(environment.webApiUrl) || req.url.startsWith(environment.adminApiUrl)) {
			// Make sure we're authenticated for API calls.  These promises will already be complete if we are.
			if (!(await this.authService.isAuthenticated())) {
				await this.authService.login();
			}

			// We're now logged in, if we possibly can be.
			const accessToken = await this.authService.token();
			if (accessToken) {
				const cloned = req.clone({
					headers: req.headers.set('Authorization', accessToken)
				});

				console.log(req.headers);
				console.log(cloned.headers);
				return await lastValueFrom(next.handle(cloned));
			}
		}

		// We'll fall back to here if we couldn't get logged in, and try the request anyway.
		return await lastValueFrom(next.handle(req));
	}
}