I may think B28 belongs to DNB.
If you didnt subscribe to 5G, Maxis needs to bear the cost to pay DNB for what you consume on B28.
That is why they disallow it.

Having say that if you subscribe 5G but lock to only use 4G but not with 5G, doesnt make sense.

This post has been edited by p4n6: Nov 4 2023, 08:26 PM