public class UnitTest1
{
    void A()
    {
        Sample<string> a = new Sample<string> // IDE0028: Collection expression can be simplified
        {
            "test",
        };

        // After applying the fix
        Sample<string> a =
        [
            "test", // CS0029 Cannot implicitly convert type 'string' to 'object[]' 
        ];
    }
}

class Sample<T> : IEnumerable<object[]>
{
    public void Add(T p) => throw null;
    IEnumerator IEnumerable.GetEnumerator() => throw null;
    IEnumerator<object[]> IEnumerable<object[]>.GetEnumerator() => throw null;
}