WN2000RPT can't access, reset or update firewall via tftp

Hello everybody

I reconnected my range extender after changing router and isp.

After a solid amber for a few seconds it flashes amber 7 times then flashes green infinitely. Reboot or reset with the pin, waiting up to several minutes and with several reboots while holding the pin does not change anything.

Accessing it via terminal and "ping 192.168.1.1" gives a connection.

I tried the procedure from page https://kb.netgear.com/000064624/How-do-I-upload-firmware-to-my-NETGEAR-router-using-TFTP-on-Apple-macOS

adapting it to Linux to update the firmware as last resort, but the file transfer gets timed out every time.

"tftp> put WN2000RPT-V1.0.1.24.img"
"Transfer timed out."

Any ideas?