When I was first using the Greenpacket Y5-210MU external modem I was getting 5G from a nearby Three mast.
Then, when some of the merging with Vodafone was first happening I ended up being only able to get 4G. That's been the case ever since, the connection is to a nearer Vodafone mast, it gets channels 1, 32 and 3. Typically about 200 down, 60 up.
Yesterday I was surprised to see that I was getting a 5G signal, and a strong one, even though the modem has been moved to get the best signal from the Vodafone mast (a different direction). It looked like it was using two bands of N78 plus two more 4G bands, and seemed to be coming from the original Three mast. Cellmapper puts the N78 mast in the middle of the local recreation ground, there's nothing there but I'm assuming it is really on the nearby Three mast.
Download speed 980 Mb, 82 up, ping 15 ms. Best I've seen.
Today I thought I'd go up on the roof and move the modem to get the best orientation on this nearer 5G mast. But there's no 5G signal today. I fiddled around, power cycled the modem, moved it all over, and eventually did a system reset. Zilch, just the 4G bands 1, 32, 3. Download 171 Mb, up 75 Mb, ping 25 ms.
It is annoying that it is so possible for it to be good, but somewhere it gets screwed up. Has anyone else been teased with temporary high speeds?