Snom-specific provisioning failures after changes to your Redirection and Provisioning Service (RPS) usually occur because the phone's MAC address is still locked to the old RPS server, there is a mismatch in the encryption protocol (HTTPS vs HTTP), or the device lacks an active SRAPS (Secure Redirection and Provisioning Service) mapping.

1. Old RPS Lock-in: If you recently changed your PBX or provisioning server but did not remove the MAC address from the previous system, the phone will ignore local configuration attempts and continuously contact the old server. 
2. HTTPS to HTTP Protocol Mismatch: Snom devices have strict SSL/TLS requirements and can fail to download configuration files or firmware over HTTPS if there is a certificate trust issue (such as an "Unknown CA" error) or a deprecated cipher suite. Try modifying the provisioning URL to use https:// instead of http://. 
3. Missing or Incorrect SRAPS Mapping: The Hosted PBX uses SRAPS for zero-touch provisioning; you must ensure the MAC address is registered there with the correct new provisioning URL. Contact support to verify this. 
4. Perform a Clean Factory Reset: When an RPS change is made, a simple reboot is rarely enough; the phone must be completely wiped so it polls the network for fresh information. Factory reset the Snom phone through its web interface (Advanced > Update > Reset), or perform a manual reset. Dial **## on the keypad, hold # until it enters rescue mode, then select Settings Reset.

Review the Snom manual associated with your device to confirm the precise steps for your model here: Snom Manuals