Conditional field…Not working

Hello All…Hope all are healthy and safe..

I am trying to create a registration form. There are basic fields like name, address, email id, phone number in the form.

Code is as follows

<label> Name : (required)
[text* your-name] </label>

<label> Address : (required)
[text* your-address] </label>

<label> Mobile Number : (required)
[text* your-number] </label>

<label> Email : (required)
[email* your-email] </label>

<label> Choose City : (required)
[select* city “- Select City -” “London” “Delhi” “Mumbai” “New York” “Calcutta”]</label>

[group london]

[select* garden “- Select Garden -” “A” “B” “C” “D”]

[/group]

[group delhi]

[select* garden “- Select Garden -” “A” “B” “C” “D”]

[/group]

[group mumbai]

[select* garden “- Select Garden -” “A” “B” “C” “D”]

[/group]

[group newyork]

[select* garden “- Select Garden -” “A” “B” “C” “D”]

[/group]

[group calcutta]

[select* garden “- Select Garden -” “A” “B” “C” “D”]

[/group]

<label> Reference : (required)
[text* your-reference] </label>

<label> Co-Reference : (required)
[text* your-co-reference] </label>

[submit “Click to fill Form “]

When I select City, it automatically shows the garden in that city. But I am not receiving that garden name in the mail. I am only receiving “- Select Garden -” in the mail.

I know there is something wrong in my code. But I am not exactly getting the answer. And the surprise is I have received right answer 2 times out of 25 via same form.

Please can anybody help me…

TIA…