Wifi connected but no internet

Question

I've just install a Debian 12 on my Dell laptop 5470. Everything went fine and I can access the internet through my ethernet cable. I also configured the wifi connection in the advanced network config and everything is ok (I have the 4 bars icon saying the wifi connection is active).
However when I shift to my wireless connection I get the "No internet" message in my browser.
sudo iwconfig

lo        no wireless extensions.

enp0s31f6  no wireless extensions.

wlp1s0    IEEE 802.11  ESSID:"Livebox-9738"  
          Mode:Managed  Frequency:2.437 GHz  Access Point: A0:39:EE:78:97:38   
          Bit Rate=144.4 Mb/s   Tx-Power=22 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=67/70  Signal level=-43 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:33   Missed beacon:0

I just can't figure out where this problem comes from.
Can someone help me ?
Note: I previously had an Ubuntu 22.04 installed on this laptop and the wifi worked just fine.

///// UPDATE ///////

sudo ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute 
       valid_lft forever preferred_lft forever
2: enp0s31f6: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether 84:7b:eb:43:d9:40 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.20/24 brd 192.168.1.255 scope global dynamic enp0s31f6
       valid_lft 74685sec preferred_lft 74685sec
    inet6 fe80::867b:ebff:fe43:d940/64 scope link 
       valid_lft forever preferred_lft forever
3: wlp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether e4:b3:18:36:8a:df brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.17/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp1s0
       valid_lft 77471sec preferred_lft 77471sec
    inet6 fe80::4966:9713:1937:80ea/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

sudo ip route

default via 192.168.1.1 dev enp0s31f6 linkdown 
default via 192.168.1.1 dev wlp1s0 proto dhcp src 192.168.1.17 metric 600 
169.254.0.0/16 dev wlp1s0 scope link metric 1000 
192.168.1.0/24 dev enp0s31f6 proto kernel scope link src 192.168.1.20 linkdown 
192.168.1.0/24 dev wlp1s0 proto kernel scope link src 192.168.1.17 metric 600

ping -c3 1.1.1.1

PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
From 192.168.1.20 icmp_seq=1 Destination Host Unreachable
From 192.168.1.20 icmp_seq=2 Destination Host Unreachable
From 192.168.1.20 icmp_seq=3 Destination Host Unreachable

--- 1.1.1.1 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2027ms
pipe 2

ping -c3 bbc.co.uk

ping: bbc.co.uk: Temporary failure in name resolution

Answer 1

Ok I finally found out where the issue comes from.
It's not a software problem but a hardware problem due to the bios settings.
For those who have the same issue:

Reboot and press F2 to enter the bios.

• Go to the Power Management section then click Wireless Radio Control
• Uncheck both the Control WLAN Radio and the Control WWAN Radio checkboxes
• Save the changes and reboot

I recently had a similar wifi issue with another Dell computer and it also turned out to be a bios setting issue.
I don't know why Dell features such obscure options as it takes hours if not days before figuring out the problem.
Anyway, I hope it helps.