Slow connection speeds - Quectel EP06-E

Hi. It's my first appearance here and let me just point how useful are these "places", thankfully! A couple of weeks ago i bought a Quectel EP06-E (so for European Countries) module for a Zbt WE 1326 router. Today i managed to make it work:

[   16.728265] qmi_wwan 1-2:1.4: cdc-wdm0: USB WDM device
[   16.735575] qmi_wwan 1-2:1.4 wwan0: register 'qmi_wwan' at usb-1e1c0000.xhci-2, WWAN/QMI device,
[   16.746362] usbcore: registered new interface driver qmi_wwan
[   16.754798] usbcore: registered new interface driver rndis_host
[   16.764232] usbcore: registered new interface driver cdc_mbim
[   16.772285] usbcore: registered new interface driver option
[   16.778110] usbserial: USB Serial support registered for GSM modem (1-port)
[   16.785946] option 1-2:1.0: GSM modem (1-port) converter detected
[   16.792685] usb 1-2: GSM modem (1-port) converter now attached to ttyUSB0
[   16.800142] option 1-2:1.1: GSM modem (1-port) converter detected
[   16.806727] usb 1-2: GSM modem (1-port) converter now attached to ttyUSB1
[   16.814366] option 1-2:1.2: GSM modem (1-port) converter detected
[   16.821180] usb 1-2: GSM modem (1-port) converter now attached to ttyUSB2
[   16.828701] option 1-2:1.3: GSM modem (1-port) converter detected
[   16.835338] usb 1-2: GSM modem (1-port) converter now attached to ttyUSB3
[   16.845365] kmodloader: done loading kernel modules from /etc/modules.d/*
T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  2 Spd=480  MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=2c7c ProdID=0306 Rev= 3.10
S:  Manufacturer=Quectel
S:  Product=EP06-E
S:  SerialNumber=0123456789ABCDEF
C:* #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=83(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=85(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=87(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=86(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=04(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
E:  Ad=89(I) Atr=03(Int.) MxPS=   8 Ivl=32ms
E:  Ad=88(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms

Here the network config:

config interface 'wwan'
        option proto 'qmi'
        option device '/dev/cdc-wdm0'
        option apn 'internet.it'
        option auth 'none'
        option pdptype 'ipv4'

Sadly, after a couple of speed tests i realized how slow it is.
Here a demonstration:

I've noted a hideous bufferbloat (about 3s in Downlad!). That bothering me a lot because i can't find what the problem is. I post a couple of things i believe that are useful:

root@OpenWrt:~# uqmi -d /dev/cdc-wdm0 --get-data-status
"connected"
root@OpenWrt:~# uqmi -d /dev/cdc-wdm0 --get-signal-info
{
        "type": "lte",
        "rssi": -76,
        "rsrq": -17,
        "rsrp": -108,
        "snr": -4
}

I've noted a low SNR values (in frequently occasion a extremely low values, about -85 dBm!). I think it's not a problem of signal level, because in the past, i was able to connect in the same spot with more decent speeds. I think that i've done the right steps to configure the modem. I appreciate a lot whoever gives me a helping hand. Thanks

Hey there. In my limited experience with WWAN modules in OpenWrt and based from the signal info that you posted. I would lean towards this as a signal reception issue. RSRP being -100 dBm is equivalent to being in the edge of the tower range.

Here's mine for comparison using the same EP06-E though I am not from Europe.

root@Xiaomi:~# uqmi -d /dev/cdc-wdm0 --get-signal-info
{
        "type": "lte",
        "rssi": -35,
        "rsrq": -9,
        "rsrp": -66,
        "snr": 132
}

I have this modem but I bought with router Gl.Inet GL-E750 Mudi.
EP06-E does not allow fast LTE speeds with some European carriers.
EP06-A allows fast speeds but it is for US market.
In Microtik forum there is thread on EP06-E modem, some tried to upgrade modem firmware.
There is absolutely no support on this modem from GL.Inet which I consider scandolous.