The 24h delay was the issue.
@Alejandro so the problem is that you don't have enough free memory. You could try shutting down NodeBB and redis before running the build, but the only other way I can think of is to add more memory space to your server. Maybe there's a way to add swap?
@PitaJ we can't do that at this time, it seems like it is working good, in few weeks we would acquire more ram if it's the problem.
Thank you very very much!