Email is not sending

giving error: Trying to access array offset on value of type null

my controller function

    // Validate the request
        $validated = $request->validate([
           'full_name' => 'required|string|max:255',
           'email' => 'required|email|max:255',
           'phone' => 'required',
           'subject' => 'required|max:255',
           'message' => 'nullable|string',
        ]);
       // dd($validated);
        Contact::create($validated);
       // Send the email

     // Prepare the email data
     $data = [
        'full_name' => $validated['full_name'],
        'email' => $validated['email'],
        'user_message' => $validated['message'],
    ];
    // Mail::to('[email protected]')->send(new ContactMail($validated));
    Mail::send('emails.contact', $data, function ($message) use ($data) {
        $message->to('[email protected]') // Replace with your email
                ->subject('New Contact Form Submission')
                ->from($data['email'], $data['full_name']);
    });

data is passing to the blade file on both way through Mailable class or PHP and when i use dd and check data is receving in emails contact blade file and also i test with bank blade file still giving error. my blade file is:

      <h1>New Contact Form Submission</h1>
    @php
          dd($full_name);
       @endphp
  <p><strong>Full Name:</strong> {{ $full_name }}</p>
 <p><strong>Email:</strong> {{ $email }}</p>
 <p><strong>Message:</strong></p>
  <p>{{ $user_message }}</p>