networking – Wifi Speed VERY SLOW – Ubuntu 20.04 HP Elitebook 745

I see a several posts about slow wifi and they haven’t been answered. My laptop HP Elitebook 745 is currently using Ubuntu 20.04 and its Linux kernel is 5.8.0-38-generic. My other laptop with Windows and phone is showing speed of average 100Mps for download while this laptop is 7Mbps download.

as for lshw -c Network

  description: Wireless interface
  product: BCM43228 802.11a/b/g/n
  vendor: Broadcom Inc. and subsidiaries
  physical id: 0
  bus info: pci@0000:02:00.0
  logical name: wlp2s0b1
  version: 00
  serial: 18:cf:5e:2b:00:2b
  width: 64 bits
  clock: 33MHz
  capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
  configuration: broadcast=yes driver=b43 driverversion=5.8.0-38-generic firmware=666.2 ip= latency=0 link=yes multicast=yes wireless=IEEE 802.11
  resources: irq:32 memory:d4800000-d4803fff

I’ve already disabled the wifi power off by setting in /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf like this below:

wifi.powersave = 2

I’m still not having any luck increasing my speed. Any suggestions will be much appreciated. Thanks.