After setting up my static IP address, I can't SSH or Ping to the board anymore. The board shows up on my router list of connected devices, and the Pi Hole works normally. I flashed a new SD card and went step by step to see what was causing the problem. I resize the filesystem, update and upgrade the system, then I set up the static IP, so this happens. I tried both by /etc/netwkork/interfaces and by nmtui. This is what my /etc/network/interfaces file looks like: 

 

auto lo
iface lo inet loopback
iface eth0 inet static
address 192.168.25.160
netmask 255.255.255.0
gateway 192.168.25.1

 

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.25.160
netmask 255.255.255.0
gateway 192.168.25.1

This way is correct.

Thanks @Igor!!