Duplicated tags in database

[beataburczyk]

Not sure if this is intentional (I don't think so) or maybe Readme file is missing with some important information about MariaDB.

My setup:
Laravel: 9.42.2
PHP: 8.1.12
MariaDB: 10.7.3-MariaDB-1:10.7.3+maria~focal

I have seed db with new tags and their translations, at this point all was fine I have resulted with few items in db with eg. name:
name => {'pl':'obiad', 'en':'dinner'}

Then, when try to seed products using:
'tags' => ['obiad']
I result with new tag in database (what is not correct to me, is a duplication)
name => {'pl':'obiad'}

My app locale is set to 'pl' as you can spot from order of translation, so during the tag seeding I had:
$tag = Tag::findOrCreate('obiad');
$tag->setTranslation('name', 'en', 'dinner');
$tag->save();

Due to construction of my product model via factory i was using this part of docs to add tags:
$newsItem = NewsItem::create([
'name' => 'The Article Title',
'tags' => ['first tag', 'second tag'], //tags will be created if they don't exist
]);

'//tags will be created if they don't exist' - this part fails, in my case create tag even if it exists, no error just new items in DB

Will appreciate any explanation of this behaviour. Thanks in advance!
Beata