Webhook receiver stopped working after upgrade from .net 6 to .net 8. Below is the controller and method that was working in .net 6 anymore.

 [Route("api/[controller]")]
 [ApiController]
 public class EController : Controller
 {
     [HttpPost]
 [Route("/api/webhooks/incoming")]
 [ProducesResponseType(StatusCodes.Status200OK)]
 [ProducesResponseType(StatusCodes.Status400BadRequest)]
 [ProducesResponseType(StatusCodes.Status500InternalServerError)]
 public async Task<IActionResult> Post(object message)
 {
     try
     {
         ResponseModel model = JsonConvert.DeserializeObject<ResponseModel>(message.ToString());
         

         await manager.handleNotify(model);


         return Ok(model);
     }
     catch (Exception ex)
     {
         Logger.Error(ex, "Failure to access incoming webhook post");
         return StatusCode(StatusCodes.Status500InternalServerError, ex.Message);
     }
     
 }
 }

Packages installed: Microsoft.AspNet.WebHooks.Receivers.Custom
Microsoft.AspNet.WebHooks.Receivers.Generic

Program.cs

var config = new HttpConfiguration();
config.InitializeReceiveGenericJsonWebHooks();
config.InitializeReceiveCustomWebHooks();