no netword after firmware update to 9.6.3

Hello,

I bought a ATEM 1 M/E Production Studio 4K from a friend witch workt fine.

at home i installed the latest software 9.6.3.
after a reboot i connected the USB cable to change the IP adress.
i started the ATEM setup software witch asked to upgrade the sofware from the switcher.

the update went wel and after the reboot form the switcher a had a nice screen from the mulivieuw.all workt wel, no errors

i started again the atem setup software to change the IP adress.
my home network is 192.168.2.* Subnet 255.255.255.0 router 192.168.2.254
is looked up a free ip adress and changed the switcher to it.
ip 192.168.2.20
subnet 255.255.255.0
router 192.168.2.254

after save, i removed the USB cable and rebooted the switcher.

I started ATEM software controle but could not find the switcher.
i added the IP adress manualy but stil no connectie.
i used a IP scanner to search the network but the switcher was not found. all other netword devices were found

the light from the ethernet connection on the back of the switcher blicked as if receiving data.

what did i do wrong.
is there a way to role back the update. of degrade to older firmware

P.S. this is nog my first switcher.