What would be a good approach to make a maze for a mobile game?

Originaly I asked this in answerhub but recently I started to think that the forum is more correct for it.

I already have a project in which I spawn a maze actor, in the constructor I create many cubes as subobjects then I place and scale them according to a grid generated in the game mode. It seems that this approach produces too many components because my phone runs with reduced fps, and there are enemies left to be spawned yet. I thought about joining the meshes in one component but I don’t know how to do that on my own nor have found a command to do it. About the navmesh I put a navmeshboundvolume guessing where the maze would and tried using the console command “RebuildNavigation” and it didn’t recognized the command, how am I supposed to generate the navmesh after constructing a maze? I saw the MieszkoZ’s video about active tiles and many of his answers but most of it seems inapropiate for a “little” map that is generated once.

EDIT: I tried replacing the boxes with one procedural mesh component, now besides being slow the walls don’t render. ¿Is the problem my project or my phone? I have a Galaxy J1.