The Coin Master invitation link changes every time you modify the app’s language. Therefore, if you added your link to Sticker Master and later changed the language on Coin Master, the invitation link you entered will no longer be valid and must be updated.
To update the link, copy your new invitation link from Coin Master in the current language and paste it into the dedicated section on Sticker Master, accessible at: Profile > Coin Master.
Remember that this process will need to be repeated for any further language changes on Coin Master.
Note: Always ensure you’re using the correct link to avoid issues when trading with other users!