Ok! After completely erase all Locus data/folder/cache and made a clean install I came to the following conclusion, if I have a folder with more than two maps each in his respective folder Locus only sees the first two folders/maps.
Ex: mnt/extSdCard/Maps/Raster and in the folder Raster I put for example 15 maps. Locus is only able to see the first two maps (named by number, the others are ignored).
I hope this makes sense.
Thanks