Hi ​@Ninko 

This is the info that I have found on-line with regards to your post:-

If RCS chat isn't working, ensure Wi-Fi/data is on, check RCS is enabled in Google Messages settings (toggle off/on if needed), update Google Messages & Carrier Services, clear cache/data for both apps, restart your phone, or try toggling Airplane Mode, but if it says "disabled by carrier," contact them, as network issues or carrier restrictions are common causes. 

1. Check Internet: Ensure you have strong Wi-Fi or mobile data.
2. Enable RCS: In Google Messages > Profile Icon > Settings > RCS chats, make sure it's on; toggle it off and on.
3. Update Apps: Get the latest Google Messages and Carrier Services from the Play Store.
4. Restart Phone: A simple restart often helps.
5. Toggle Airplane Mode: Turn Airplane Mode on for a few minutes, then off.

• Clear Cache & Data: Go to your phone's Settings > Apps > Messages > Storage > Clear Cache & Clear Data (and do the same for Carrier Services).
• Force Stop Apps: After clearing data, force stop Messages and Carrier Services before reopening.
• Check Default App: Make sure Google Messages is your default SMS app.
• Dual SIM: If you have two SIMs, ensure the "Call SIM" is set as the "Data SIM" in your phone's Network settings.
• Google Account: Visit myaccount.google.com/phone to ensure your number is correct and auto-verification is on. 

You don’t say what make/model phone you are encountering the problem with so I can’t narrow down the advice I can give you.

You can do an internet search to determine further steps that may help e.g. RCS chat not working stuck on verifying (add make/model of phone) as there is a LOT of information on ‘How to’ out there e.g. 

https://support.google.com/messages/thread/8641879/rcs-chat-stuck-on-setting-up-trying-to-verify?hl=en

If all else fails then it may be worth contacting iD Mobile Customer Services by any one of the following ways:-

Hi ​@Ninko 

Thank you for getting in touch, and I completely understand how frustrating it must be to have RCS chats stuck on “verifying” after porting your number.

It sounds like you may be experiencing a network-side provisioning issue, rather than a device problem, since you’ve already tried standard troubleshooting steps given above. 

Lamiya