20.04 – Ubuntu 20.05 not detecting my ram

I had 4gb ram on a old desktop pc, I just installed 4gb extra ram. Bios detects 8gb, windows detects it. But linux only sees 4gb.

uname -a:

Linux appie-imedia-S2185 5.4.0-70-generic #78-Ubuntu SMP Fri Mar 19 13:29:52 UTC 2021 x86_64  
x86_64 x86_64 GNU/Linux

free -m:

total        used        free      shared  buff/cache   available
Mem:           3365        1278         806         100        1280        1753
Swap:          3514           0        3514

cat /proc/meminfo | grep -i memtotal

MemTotal:        3446176 kB

But then lshw notice there is 8gb:

lshw -short | grep ‘System Memory’:

/0/14                        memory         8GiB System Memory

Since Bios, Windows and lshw sees the 8gb, the problem should be with linux…. Anyone any clue on how to make linux see and use all my ram?