My power grid underground is not working at all. Im playing on 2.0.77 and the mod's version is 1.6.24

Hello. Due to a bug in version 1.6.24, the cable connecting the surface and underground can be severed by the user. You can restore the cable connection by using the command below.

/c local linox_A = game.get_surface("linox-planet_linox")
local linox_B = game.get_surface("linox-surface_under-1")
if linox_A and linox_B then
local lppn1 = linox_A.find_entity("linox-special_circuit-pole", {0,2})
local lppn2 = linox_B.find_entity("linox-special_circuit-pole", {0,2})
if lppn1 and lppn2 then
local lppn1_connector = lppn1.get_wire_connector(defines.wire_connector_id.pole_copper, true);
local lppn2_connector = lppn2.get_wire_connector(defines.wire_connector_id.pole_copper, true);
lppn1_connector.connect_to(lppn2_connector, false, defines.wire_origin.script);

lppn1_connector = lppn1.get_wire_connector(defines.wire_connector_id.circuit_red, true);
lppn2_connector = lppn2.get_wire_connector(defines.wire_connector_id.circuit_red, true);
lppn1_connector.connect_to(lppn2_connector, false, defines.wire_origin.script);

lppn1_connector = lppn1.get_wire_connector(defines.wire_connector_id.circuit_green, true);
lppn2_connector = lppn2.get_wire_connector(defines.wire_connector_id.circuit_green, true);
lppn1_connector.connect_to(lppn2_connector, false, defines.wire_origin.script);

end
end

Running Lua Commands will cause you to lose the achievement feature. If you find this regrettable, you can use the Mod below to run Lua Commands.

https://mods.factorio.com/mod/some-luaconsole