JSON serializer writes excessive ']'

I have an API controller, which accepts HTTP requests and return some result. All work properly, but when it gets PUT request, serializer writes data with the excessive ']', so when I want to get data from JSON file after this, the program returns errors.

Controller API code:

using Gazda.Models;
using Gazda.Services;
using Microsoft.AspNetCore.Mvc;
using System;

// For more information on enabling Web API for empty projects, visit https://go.microsoft.com/fwlink/?LinkID=397860

namespace Gazda.Controllers
{
    [Route("/api/Comment")]
    [ApiController]
    public class CommentController : Controller
    {
        public CommentController(JsonFileCommentService jsonFileCommentService)
        {
            JsonFileCommentService = jsonFileCommentService;
        }
        public JsonFileCommentService JsonFileCommentService { get;}

        [HttpPost]
        public IActionResult Post([FromForm]Comment comment)
        {

            comment.Id = Guid.NewGuid().ToString();

            JsonFileCommentService.AddComment(comment);

            return Ok(comment);
        }

        [HttpGet]
        public JsonResult Get()
        {
            var comments = JsonFileCommentService.GetComments();
            return Json(comments);
        }

        [HttpPut]
        public IActionResult Put([FromBody] string id)
        {
            JsonFileCommentService.ChangeLike(id);
            return Ok("Successfull PUT");
        }

    }
}

JSON file before PUT-request:

[
  {
    "Id": "9d2a1e79-cd44-43a0-88cd-0d8868cd723e",
    "Name": "Yurii",
    "Text": "\u043D\u0430\u0434\u0437\u0432\u0438\u0447\u0430\u0439\u043D\u043E \u0441\u043C\u0430\u0447\u043D\u043E",
    "isLiked": false
  },
  {
    "Id": "e8577368-9634-40cc-ba30-7e3efd8f7ec3",
    "Name": "Arch",
    "Text": "super taste",
    "isLiked": true
  }
]

JSON file after PUT-request:

[
  {
    "Id": "9d2a1e79-cd44-43a0-88cd-0d8868cd723e",
    "Name": "Yurii",
    "Text": "\u043D\u0430\u0434\u0437\u0432\u0438\u0447\u0430\u0439\u043D\u043E \u0441\u043C\u0430\u0447\u043D\u043E",
    "isLiked": false
  },
  {
    "Id": "e8577368-9634-40cc-ba30-7e3efd8f7ec3",
    "Name": "Arch",
    "Text": "super taste",
    "isLiked": false
  }
]]

Service code:

using Gazda.Models;
using Microsoft.AspNetCore.Hosting;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.Json;

namespace Gazda.Services
{
    public class JsonFileCommentService
    {
        public JsonFileCommentService(IWebHostEnvironment webHostEnvironment)
        {
            WebHostEnvironment = webHostEnvironment;
        }
        
        IWebHostEnvironment WebHostEnvironment { get; set; }

        private string JsonFileName
        {
            get { return Path.Combine(WebHostEnvironment.WebRootPath, "data", "comments.json"); }
        }

        private void SerializeComments(List<Comment> comments)
        {
            using (var outputStream = File.OpenWrite(JsonFileName))
            {
                JsonSerializer.Serialize<IEnumerable<Comment>>(
                    new Utf8JsonWriter(outputStream, new JsonWriterOptions
                    {
                        SkipValidation = true,
                        Indented = true
                    }), comments);
            }
        }
        
        public List<Comment> GetComments()
        {
            try
            {
                using (var jsonFileReader = File.OpenText(JsonFileName))
                {
                    return JsonSerializer.Deserialize<List<Comment>>(jsonFileReader.ReadToEnd(),
                        new JsonSerializerOptions
                        {
                            PropertyNameCaseInsensitive = true
                        });
                }
            }
            catch
            {
                return new List<Comment>();
            }
        }

        public void AddComment(Comment comment)
        {
            if(comment==null)
            {
                throw new ArgumentNullException();
            }

            var comments = GetComments();

            comments.Add(comment);

            SerializeComments(comments);
        }

        public void ChangeLike(string id)
        {
            var comments = GetComments();

            var comment = comments.First(x=> x.Id == id);

            comment.isLiked = !comment.isLiked;

            SerializeComments(comments);
        }
    }
}

The most interesting thing, that service serialize data clearly, when controller gets POST-request. So, I don't understand, why it's happening. Thank you in advance!!!

P.S. For additional information here is my React code, where I make put request:

import React, { Component } from 'react'
import axios from 'axios';

export default class Comment extends Component {
    constructor(props){
        super(props);

        this.click = this.click.bind(this);
    }
    
    click(event){
        event.target.classList.toggle("likes");
        console.log(this.props.comment.id)
        axios({
            method: 'PUT',
            url: '/api/Comment', 
            data: JSON.stringify(this.props.comment.id), 
            headers:{'Content-Type': 'application/json; charset=utf-8'}
        })    
             .then(resp=>console.log(resp.data))
             .catch((err) => { throw err });
    }

    componentDidMount(){
        console.log("I'm inside component")
    }

    render() {
        return (
            <div>
                <div className="comment-item">
                    <div className="comment-name">{this.props.comment.name}: 
            </div>
                    <div className="comment-text">{this.props.comment.text}</div>
                    <i className="fas fa-heart" onClick={this.click}></i>
                    
                </div>
            </div>
        )
    }
}