@Ar5had07 according to the API Signal Request Return Info the 4G Signals you are getting are extremely good, there thundering in, almost as though your sitting on top of the Cell Mast -
RSSI -51dbm
RSRP -78dbm
SNIR 16db
the Cell ID you are connected to is 8611586 which a Band 3 Cell Sector Firing South and located at the M25 and Watling Street which Im assuming very close to you, but this Site does not appear to Transmit any 5G Signal, so the 5G will be coming from another Mast.
Time permitting Im going to try and come up with some suggestions in order to process eliminate them but for now lets just concentrate on the Router and your Antenna Set Up.
Just so Ive got everything clear in my head, just to confirm the Router is a Huawei Pro 2 (112-373) which doesn't have any External Antenna Port options from New and out of the Box, but you've had the Router Modified for 8 x External Antenna Ports (who did this by the way), so Im going to Assume the Mod is designed to give you 2 lots of 2x2 MiMo on 4G (4 Ports) and 2 lots of 2x2 MiMo on 5G (another 4 Ports), so 8 Ports in total, correct?
Im am also going to assume, due to the complexity of the conversion, that after the Mod All of the Huawei Internal Antennas are now disconnected?, so the Router is now External Antennas Only, All or Nothing Mode, there's a reason where Im going with this so bare with me, the External Antennas that you are using on the Router are 2 lots of Ponyting 2x2 MiMo 4/5G Directional Antennas, hopefully each 2x2 Mimo Antenna is on the correctly Phased 4G 2x2 Mimo Ports on the Router and 1 x 2x2 Mimo Bluespot 5G Directional Antenna which again hopefully is connected to the correctly Phased 5G 2x2 Mimo Ports on the Router, so 2 of Leftover Ports on the 5G Ports are not connected to anything, just left empty, is all this correct so far?
Now, the Antennas, Poynting Antennas know them well, there good, Bluespot Antenna don't know them so I cannot comment on them, but one thing I did pick up is they are calling this Antenna a 5G Only Antenna for the UK, which is not strictly correct they appear to be 3400 to 3800mhz which is probably fine for the initial 5G Band (n78) that EE and the Other UK Networks use, but is out of spec for the newer 700Mhz 5G (n28) that EE are currently Rolling Out now, plus any future n1, n3 and n7 Band that are planned for the future.
The Router, some of the Huawei 5G CPE Routers and almost All of the Non External Antenna models have form memory around 12 x Phased Internal Antennas, basically a mix and match of Aerials at different Phase Angles at different frequency Bands, and in some cases more Antennas that what the Router really needs, idea being is that the Router will Vote on the best Antenna to use vs Signal and Location, In your Admin UI Home Page Software there's probably something in there like a Signal Location Program that Tests different Router Locations for best Signal, the test take a few mins and will test for both 4G and 5G and give you the option to save and name each Test etc. now thinking outside the box, the Internal Antennas all 12 of them have now been discounted and replaced with, in effect, 6 External Antennas (2 in each Antenna Panel and 2 of them left empty) so Im wondering id the Router has run a Internal Signal Vote or Location Test in the background and has now miss matched or confused itself. The Router doesn't know these are now no longer its own Antennas, point of interest on the Huawei 5G Models that have External Antenna Ports can actually Software Vote as a best mix of Internal and External Signals.
Couple of Questions,-
How was the Router Mod done and do you know the Antenna Port configurations and MiMo Phased Pairs.
Do you know whether your Router supports 5G Band n28, fairly sure the Pro 2 does but need confirmation and where did the Router originate from, is it Networked Locked or Firmware locked down by a Network.
Which Direction are your Antennas Pointing.
On the Single Bluespot 5G Antenna there are 2 x N Type Connecters on the Back, if this Antenna is Outside did you Water and Weather Proof the Connecter and what Coax Cable are you using.
When you spoke to EE Tech Support did they mention anything about any recent Works being done in your Area.
Do you per chance have any Pics available when the Router was giving you 5G (or good Download Speeds), in Particular the 5G Signal and which particular 5G Band(s).
Based on the above regarding the Routers Aerial Voting, my first call would be to do a Full Factory Reset of the Router (make sure you have All he Relevant Original Passwords at hand for both the the Admin and WiFi Passwords before doing a Reset). Take out the Sim Card before Resetting and after the Reset put the Sim back in and check the APN Profile is correct for EE, if youve have changed any Router Settings for it to talk to your other Routers or Devices these will also probably need to re configured again with the Router.
