LattePanda 3 Delta randomly powers off

Hello,

my LattePanda Delta 3 arrived.

I immediately installed Ubuntu on it:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.1 LTS
Release:        22.04
Codename:       jammy

Unfortunately it randomly just powers off. Sometimes after some hours but it never kept running for three days in a row.

What could be the reason?

I cannot replace my raspi until this is solved.