5G Mobile doesn't support streaming 2160p60 (4K)

[Uberseehandel]

I have just subscribed to EE's unlimited 5G Mobile Broadband package. By changing the EE router's LAN IP network address and turning off NAT, the existing gateway device connects to the Internet without issue.
So achieving 120 -  150 Mbps download speed, against 50 the DSL's 50 Mbps.
But what is going on?
Streaming at 2160p60 is continuously buffering, to the point where it is unwatchable. Download speed has improved 2 to 3 times, but streaming YouTube fails.
How do we fix this?

[lukerobinsonin2]

it is probably a problem with youtube itself, youtube can be slow sometimes

[EssexBoyEE]

How are you streaming 4K? Ie, on what Device and using what method. 

[Uberseehandel]

Luke,
Thanks for responding. it isn't YouTube, I have tested on a 50 Mb connection it plays 4K without buffering. I know there can be issues with YouTube but this is consistent across different playout devices and goes away when I revert to the landline.😓

[Uberseehandel]

@EssexBoyEE 
I have tried streaming on a modern i7 laptop playing out on a 4K display. I have also tried streaming from a smart TV that plays 4K60fps videos/films without buffering.
What I am now getting is buffering, giving every sign that my connection is being capped. 2160p60 always buffers, but at 5 am a 2160p50 vid only had minimal buffering.
This issue does not occur on the BT landline which at best is a 50 Mb connection, whilst the EE 5G tests at 120+ Mbps.
It feels like throughput capping.

[Uberseehandel · Accepted solution]

Update
About 30 minutes ago, service returned to normal and vids streamed properly. What was happening, I do not know, I doubt I ever will. @EssexBoyEE  and @lukerobinsonin2  thanks for responding I'll mark this closed, cause unknown, however. 🤔