Suddenly no internet in guest system!

I use Opensuse 15.1 i have installed androidx86_64 as a guest system, it runs for over 3 years. i had a internetconnection, i could use apps etc. but since yesterday i can´t connect to the internet with the guest system in the host system all works fine. What could be the reason? There haven´t been an update and i haven´t changed anything. 
The settings in nic are: bridge br0: Hostdevice eth0
devicemodel: e1000

The qemu Version is from the opensuse repo: 3.1.1