Webhook validation failure in EU

Webhook validation failure in EU

Recently received a notification from Zoom related to webhook validation failure for one the Admin Apps published by my company. The webhook is getting validated in the other similar Apps with the same endpoint, however, getting failure for EU.

Tried sending the manual request through marketplace, however, not receiving the request. Also tried calling the URL from a browser and I could receive the request then.

Could I please get some pointers here to see what could be the issue?