iPhone X ICloud not syncing

Thank you for your quick response, I will explain the situation further. On 3 November I bought my IPhone X and in the car ride home I set it up as a new iPhone because I had no wifi and I couldn’t wait. Than at home I synced it to iCloud over WiFi and 4g, for over a week nothing happened and nothing synced with my other phones - I have over 25k photos on iCloud but after a week not even one of them got synced and neither did the new pictures I took sync with ICloud itself. Then I thought about making a backup of my iPhone 7 Plus and restoring my IPhone X with it - to change the setup I had once done as a new iPhone and to now set it up through ICloud and the back up. That was a failed operation - the photos all 25 k of them are now on my IPhone X but it’s still not syncing any new photos. All the time I’m connected to either WiFi or 4G - My area is Greece. Please help me as I’m desperate to find a solution. Thank you in advance.