I am using VS Code with the paid PHP extension as well as the official Laravel extension. In my resource files that use a @mixin \App\Models\MyModel comment, all properties are correctly identified based on the generated vendor/laravel_ide/_model_helpers.php file, but after a few seconds, the information is lost and I get the error PHP6602 that every property I am accessing is accessed via Model::_get() magic method.
So this is the code after starting VS Code:

And as soon as I click into a property:

At first I thought it was an error in the Laravel extension because the helper file was not generated at all, but that was an issue on my side and now it is. This error I am reporting here does not seem to be caused by the Laravel extension according to https://github.com/laravel/vs-code-extension/issues/521#issuecomment-3697520874 and the following comments.