Hi! I understand you're having trouble enabling background services for the VCheck24 app on your iPhone 12 Pro running iOS 18.6. Let's work through this together to get it sorted out.

First, to check if Background App Refresh is enabled properly, please follow these steps:

1. Open the Settings app on your iPhone.
2. Go to General.
3. Tap on Background App Refresh.
4. Make sure Background App Refresh is turned ON at the top.
5. Scroll down the list and locate the VCheck24 app.
6. Ensure that the toggle next to VCheck24 is also turned ON.

Sometimes, if the global Background App Refresh is off, individual apps cannot use it. So step 4 is key.

If you have already done that or the option is greyed out, please let me know. It can also be helpful to check the app’s permissions:

1. In Settings, scroll down and tap on VCheck24.
2. Ensure all the relevant permissions are allowed, especially cellular data if you use that.
3. Restart your phone after adjusting settings to solidify changes.

If these settings look correct but the app still can't enable background services, it could be an iOS bug or a conflict caused by recent updates.

One more advanced step you can try:
- Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This resets network settings without erasing data, which sometimes helps with background refresh issues.

Please try these and let me know how it goes. If the problem persists, we can look deeper or check for any known issues with iOS 18.6 and VCheck24 compatibility. Also, I can provide direct assistance to notify our developers if needed.

Are you satisfied with this approach so far?