@Porchbeers Not exactly sure from the description, but you mention trying "every match of neutral" which sounds a little off.  There's only one way to connect the neutrals - a single shared bundle with all of the whites including the wemo's (assuming they were all shared before you installed it).  If the bundle is too big create a second bundle with a short jumper between.  The flashing does suggest it is something wrong with the neutral.  If the neutrals weren't all joined before you may need to figure out what all of the wires are doing in case something is wired differently that you expect.