Angular 6 - multiple router outlets

The problem is you are trying to send an Auxilliary route as a string. routerLink evaluates the value on RHS as string. That is why you get to see strange characters in your route. To make this work, you need to try as follows -

<a [routerLink]="[{ outlets: { example: ['example1'] } }]">Example</a>

In your case

 <a [routerLink]="[{ outlets: { register: ['register'] } }]">Example</a>//outletName:['route-path']

EDITED

Named Child outlet relative to ROOT route does not work and seems like a BUG

A workaround is mentioned in the comments section.

OR

You can change configs like below -

{
    path: '', component: LoginComponent
 },
 {
    path: 'example1', component: ExampleComponent, outlet: 'example'
 }