That was everything I did to set up my own Webflow webhook, which is still working fine.
I have run out of ideas as what else could be the issue.
Perhaps you might want to contact Webflow support to see why the form submissions aren’t being sent.
You should also double check that the scenario is turned on, and there are no pending data in the Webhook queue (just switch the scenario toggle off and on again and it will prompt you if there is old data).