Creating a new database returns ORA-27125

I have made a new installation of 18.3 database on Red hat 7.5 on VM.

The server has 32GB of RAM.

I created 2 databases with total SGA+PGA=8GB. When I try to create a third one I'm getting ORA-27125.

When I type "free" I get the following:

                total             used          free            shared        buff/cache   available

Mem:       32781764     1344612    15954652    13444016    15482500    17601756

Swap:      33554428           0         33554428

It looks like system does not use any SWAP.

Below are the kernel parameters I followed Oracle documentation.

/etc/sysctl.conf:

kernel.sem=250      32000      100     128

kernel.shmall=4194304

kernel.shmmax=17179869184

kernel.shmmni=4096

kernel.panic_on_oops=1

fs.file-max=6815744

fs.aio-max-nr=1048576

net.ipv4.ip_local_port_range=9000 65500

net.core.rmem_default=262144