I just reprojected with PostGIS tree layers using this function:
select UpdateGeometrySRID('schema', 'table', 'geom', 3857)
These tree layers are contiguous. The problem is, when I open it on QGIS to check if they are reprojected well, just one of them is in the correct ubication. I have another layer to intersect and obviously, it doesn't return the expected result as just one of the layers to intersect with is in the correct ubication.
I tried to reproject them directly on QGIS exporting in local with the correct projection, and with this way the reprojection was done well. But I keep asking why the reprojection with PostGIS didn't work.