@qpassa Ok, from what I see the DHCP config matches the IP setup and I can’t find any typo in there. Even tested the config posted on a test VM.
Maybe there is an interface linked in another config. Please run
grep INTERFACE /etc/default/isc-dhcp-server and post output here.
Other than that you might also run the following commands and post output here:
systemctl restart isc-dhcp-server journalctl -u isc-dhcp-server
On the last command you want to hit Shift-g to jump to the bottom of the log. Then copy and paste what you see. Then hit ‘Q’ to exit journalctl.