I've replicated this on:
- CiviCRM 5.57.4, Drupal 7.94, webform 7.x-4.25, Civi webform 7.x-5.8
- CiviCRM 5.50.1, Drupal 9.4.5, webform 6.1.3, Civi webform 6.2.1
When registering for an event (paid or not - I've tried both) via a webform, the receipt does not send. In the case of the paid event, both contribution and event receipting was turned on (per this webform event registration - no receipts from contribution page?); the contribution receipt went out but the event receipt did not. In the case of the non-paid event, no receipt went out.
Receipting works correctly when registering from the Civi-generated form, so either I'm missing something in the webform configuration or there's another issue. Any help appreciated!