I am trying to do a mapping using rtabmap. However, at some random points, it stops from updating the map as it should, leaving some empty regions:

I have tried changing the values of different parameters, such as increasing the detection rate or setting map_always_update to true. But the situation hasn't improved.
Does anyones has a clue on what can I do?
Pd: I am running my simulations in Virtual Machine so I don't know if everything works fine and it is a problem of the resources of the Virtual Machine.