Some of the webhooks are failing with 500 status

[user072319]

I've a Shopify app and have added the orders/create webhook. I'm passing 200 success code from the webhook file.

header('X-PHP-Response-Code: 200', true, 200);

Some of the webhooks are failing and returning 500 code but some are success with 200 code. I've created webhooks with older API version 2021-04 but in the App Setuop I've updated the webhook version to 2021-07. Is this a problem? Or any other reason for the failure?