Please run iperf3 -c 127.0.0.1 and post results here to make router database

GL.iNet GL-B1300 runing vendor's latest firmware as of today 4.3.11, release3, compile time 2024-03-20 22:21:48(UTC+08:00)

root@GL-B1300:~# ubus call system board
{
        "kernel": "5.4.179",
        "hostname": "GL-B1300",
        "system": "ARMv7 Processor rev 5 (v7l)",
        "model": "GL.iNet GL-B1300",
        "board_name": "glinet,gl-b1300",
        "release": {
                "distribution": "OpenWrt",
                "version": "21.02.2",
                "revision": "r16495-bf0c965af0",
                "target": "ipq40xx/generic",
                "description": "OpenWrt 21.02.2 r16495-bf0c965af0"
        }
}
root@GL-B1300:~# iperf3 -c 127.0.0.1
Connecting to host 127.0.0.1, port 5201
[  5] local 127.0.0.1 port 52952 connected to 127.0.0.1 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   155 MBytes  1.30 Gbits/sec    0   1023 KBytes
[  5]   1.00-2.01   sec   150 MBytes  1.25 Gbits/sec    0   1023 KBytes
[  5]   2.01-3.01   sec   151 MBytes  1.27 Gbits/sec    0   1023 KBytes
[  5]   3.01-4.01   sec   141 MBytes  1.18 Gbits/sec    0   1023 KBytes
[  5]   4.01-5.00   sec   138 MBytes  1.16 Gbits/sec    0   1023 KBytes
[  5]   5.00-6.00   sec   155 MBytes  1.30 Gbits/sec    0   1023 KBytes
[  5]   6.00-7.00   sec   148 MBytes  1.23 Gbits/sec    0   1023 KBytes
[  5]   7.00-8.00   sec   149 MBytes  1.25 Gbits/sec    0   1023 KBytes
[  5]   8.00-9.00   sec   150 MBytes  1.26 Gbits/sec    0   1023 KBytes
[  5]   9.00-10.00  sec   130 MBytes  1.09 Gbits/sec    0   1023 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.43 GBytes  1.23 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  1.43 GBytes  1.23 Gbits/sec                  receiver

iperf Done.