Hi,
Same issue here, the slug is initially setup with the same values and does not update even when I force it manually;

I used the basic create() method

 public function getSlugOptions(): SlugOptions
 {
 return SlugOptions::create()
 ->generateSlugsFrom('title')
 ->saveSlugsTo('slug');
 }

I got the same problem, very strange...

I've dug a bit into this since I was having the same issue.

In the HasTranslatableSlug trait, the addSlug method calls $this->withLocale(...) to set the locale at the application level through the Illuminate\Support\Traits\Localizable trait. This sets the locale at the laravel container level.

However, later on when getSlugSourceStringFromCallable is called in HasTranslatableSlug, it calls $this->getLocale() to retrieve the locale that is based to the callable in generateSlugsFrom. This call to $this->getLocale() gets the locale set at the level of the model by the translatable package in HasTranslations, but the $translationLocale defined in HasTranslations is not set by the call to withLocale(...), so it uses the initial locale set on the request.

I'm not entirely sure what the intention is with the code. For a simple fix, which I'm not sure would be the way forward since it seems to negate the need for the call to withLocale, is to add a call the $this->setLocale($locale) method from HasTranslations inside the withLocale(...) call.

So a simple way to add this functionality to you code base is to create a new Custom Trait that "extends" the base hasTranslatableSlug trait:

<?php
namespace App\Models\Traits;
use Spatie\Sluggable\HasTranslatableSlug;
trait CustomHasTranslatableSlug
{
 use HasTranslatableSlug {
 addSlug as originalAddSlug;
 }
 protected function addSlug(): void
 {
 $this->ensureValidSlugOptions();
 $this->getLocalesForSlug()->unique()->each(function ($locale) {
 $this->withLocale($locale, function () use ($locale) {
 $this->setLocale($locale); // Extra line to set the locale on the model
 $slug = $this->generateNonUniqueSlug();
 $slugField = $this->slugOptions->slugField;
 if ($this->slugOptions->generateUniqueSlugs) {
 // temporarly change the 'slugField' of the SlugOptions
 // so the 'otherRecordExistsWithSlug' method queries
 // the locale JSON column instead of the 'slugField'.
 $this->slugOptions->saveSlugsTo("{$slugField}->{$locale}");
 $slug = $this->makeSlugUnique($slug);
 // revert the change for the next iteration
 $this->slugOptions->saveSlugsTo($slugField);
 }
 $this->setTranslation($slugField, $locale, $slug);
 });
 });
 }
}

And then use that trait in your model instead.