The Mornsun LS15-13B12 AC/DC module datasheet (offline flyback , 15w) gives examples of mains input filters needed to be added to get through EMC compliance testing.
However, I don’t see how they can give such examples, as many people will be connecting secondary GND to earth, which gives far worse radiated emissions. They haven’t shown the case of secondary GND being connected to earth, which is highly common amongst likely users of this power module.
How can they give filter examples without stating whether or not the secondary GND is earthed?
Mornsun LS15-13B12 AC/DC module datasheet
https://www.mornsun-power.com/html/pdf/LS15-13B12SS-F.html