Mikrotik support first wanted me to try the latest RouterOS beta
and then told me to open a RMA warranty repair with
my distributor. They did not say if this is software or
hardware related. Looking at the other RB4011 cases
on this forum http://forum.mikrotik.com/t/rb4011-and-rb1100-ahx4-bricks-randomly/130638/1
I think iit is a hardware issue after all.
Greetings