China Unicom SIM has no 3G with China Mobile branded S5 Duo, why?

[AC Question]

China Unicom SIM has no 3G with China Mobile branded S5 Duo

Hello,

I bought a S5 dual Sim (G-9008W) in China. I only later saw that it is branded by China Mobile.

I am currently in China and with my China Unicom SIM Card I can only use EDGE.

With a China Mobile SIM Card I have 4G without problem.

I was told that the China Unicom SIM card is ready for 4G but that there is a lock on China Mobile branded cell phone to block anything higher than EDGE with non China Mobile SIM cards.

The cell phone is rooted and uses a SVA ROM from samrusung.

Anybody got an idea how to remove the lock?

Thanks a lot in advance!

Regards
Christian