Very slow download speed over LTE from Apple App Store

Hi,

after updating my iPhone X 64GB and iPad 9.7 4G to iOS 11.2.6 download and update download speed from the Apple Store (google inbox app takes about 10 minutes to download) have significantly decreased. Provider on which issue was detected: Orange Romania

Troubleshooting steps:

- Soft and Hard reset of both devices

- Sim card replacement

- Other provider sim used (Vodafone Romania)

- Network settings were reset (on both network operators)

- Restored both devices via iTunes (with backup)

- Restored both devices via iTunes and set devices up as new

None of the above helped, issue still persists.

Any ideeas gentlemen?

Kind regards,

Horia