Slow 5G speeds with NR5101

Although the speeds are better than before (200mb instead of 80mb), they're still a lot less than what I get on my mobile phone (using the same sim card).

I opened a support ticket with Zyxel over a month ago and to date they have done nothing so will be returning it and buying a D-Link DWR-2101 5G router instead which hopefully will give me the 5G speeds I'm looking for.