Hello 
This is my first submit to this forum, so please let me know what I can do to improve the post.
So I have had this problem for quite a while now. I cannot connect nor find any wifi networks on my Manjaro Machine. I tried to figure out why but didnt get very far to be honest. I can exclude, that my card is broken, since it used to work just fine when I had a dualboot with Windows 10 and Manjaro if i booted into Windows and then into Manjaro. If I was rebooting my Laptop onto Manjaro again, it would stop working.
To minimize some factors, I have now got my Laptop with Manjaro only. I should add, that I already have tried to install a package from the AUR (AUR (en) - rtw88-dkms-git) for my wifi card. It seemed to work after rebooting but now the same problem as before persists.
So here are the outputs of a few commands that I think can be helpful
ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: wlp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
link/ether c2:da:86:d5:54:0e brd ff:ff:ff:ff:ff:ff permaddr c0:b5:d7:48:c6:49
3: enp0s20f0u3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 00:e0:4c:68:19:db brd ff:ff:ff:ff:ff:ff
lspci -k
03:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8822BE 802.11a/b/g/n/ac WiFi adapter (rev ff)
Kernel driver in use: rtw_8822be
Kernel modules: rtw88_8822be, rtw_8822be
Any help would be greatly appreciated.
Welcome to Manjaro! 