K30 Pro with eu rom have 5G?

[nkwhahaha]

I brought a K30 Pro with china rom, when I insert my sim(4G) in it. It can show the 5G

And I flash eu ROM on next day, my sim can't show 5G. Then I flash back to china rom, it also can't show 5G.

I am not sure the K30 pro is losing the 5G during the flash rom. But my sim was also 4G plan. NOT 5G. The ISP was still building the 5G.

How can I make sure the K30 pro 5G function was working normal?

Thanks!

 

[nkwhahaha]

I have flash back to china rom wirh MiPhoneAssistant again. I can see the 5G logo again. maybe it need time to wait it to change.

But I also flash the eu rom again, still no 5G logo.
I am not sure is the ISP restrict the handset model(but from my test, it seem not possible)

Or the eu rom restrict the 5G frequency?
Or the ISP has some restrict for the rom, I am not sure how to do that? (I say that because my phone mi6 was china rom, it has the volte long time ago, but some also have mi6 with global rom. it doesn't have volte, until the ISP(same as mine) has some change few days ago.)