Wifi adapter not found, rtl8821ce no longer working [18.04]

When I installed ubuntu 18.04 on my HP Pavilion 15z 6 months ago, I had trouble getting the wifi driver to work. Installing the rtl8821ce repo from this post solved my problem. 6 months later, I'm having trouble again with the "No wifi adapter found". I booted into my Windows 10 and the wifi works, so my wifi card is fine.

I uninstalled and reinstalled the rt18821ce from the kernel with no problems.

cd rtl8821ce/
sudo ./dkms-remove.sh
sudo /dkms-install.sh

Then rebooted, but still no connection to wifi card.

Following the instructions on this post, I removed the rt18821ce and then installed official ubuntu package.

sudo dpkg -i rtl8821ce-dkms_5.2.5.2.1.30816.20190425-0ubuntu1_all.deb

Rebooted, still have the issue.

Here's information on the details of my network card.

sudo lshw -C network

  *-network UNCLAIMED       
       description: Network controller
       product: RTL8821CE 802.11ac PCIe Wireless Network Adapter
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       version: 00
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress cap_list
       configuration: latency=0
       resources: ioport:f000(size=256) memory:fe900000-fe90ffff
  *-network
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eno1
       version: 15
       serial: f8:b4:6a:a7:75:ff
       size: 10Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=half firmware=rtl8168h-2_0.0.2 02/26/15 latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:47 ioport:e000(size=256) memory:fe804000-fe804fff memory:fe800000-fe803fff

lspci -nnk | grep -A2 0280

02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821CE 802.11ac PCIe Wireless Network Adapter [10ec:c821]
    Subsystem: Hewlett-Packard Company RTL8821CE 802.11ac PCIe Wireless Network Adapter [103c:831a]
    Kernel modules: rtl8821ce

dmesg | grep -i firmware

[    0.474628] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored
[    1.328217] acpi PNP0A08:00: [Firmware Info]: MMCONFIG for domain 0000 [bus 00-3f] only partially covers this bridge
[    2.721778] psmouse serio1: elantech: assuming hardware version 4 (with firmware version 0x4d5f02)
[    4.700397] Bluetooth: hci0: RTL: rtl: assuming no firmware upload needed
[    4.842078] [drm] Found VCN firmware Version: 1.73 Family ID: 18
[    4.842083] [drm] PSP loading VCN firmware
[  120.770143] usb 1-2.3: r8712u: Loading firmware from "rtlwifi/rtl8712u.bin"

kernel version 5.0.0-37-generic

I have a log from journalctl -b if that helps.


The issue was that BIOS Secure Boot was On.

Even though I did turn off Secure Boot 6 months ago, my BIOS settings reset to default(maybe it updated?), so I had to turn it off again.