Webhook failing with 403 error

Hi,
Running the latest RC 4.0 version I’m getting failed webhook responses to https://www.xxxxxx.com/?wc-api=wc_stripe

I’ve set it up correctly within stripe, but in the logs I see all the events have failed webhook responses:

https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR
https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR
https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR
https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR
https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR
https://www.xxxxxx.com/?wc-api=wc_stripe%5D: (403) ERR

Any idea what could cause this to fail? I asked my web host to check if this was a caching issue, and they said they disabled caching for this url and the url is working as it should be from a server perspective.

Thanks,
Chris