I'm making a composer with 6 maps based on the same (postgis)layers and extent. The only thing that differs between them is the filter I put on two layers. I change the filter on the layers, then only refresh the map for that particular filter and lock the map. At the end it looks fine in the composer, but after exporting all maps have the same (last applied) filter. This also happens after refreshing the composer.
I'm using a clean install of QGIS 2.18.13 on macOS Sierra 10.12.6