UE4 fails to reimport ambix files

when trying to reimport an ambix file, i get the following:
LogFactory: FactoryCreateFile: SoundWave with ReimportSoundSurroundFactory (0 0 d:\Game_Projects[Top Secret Project]\prod\dl[Top Secret Project Initials]\Audio\SFX\Global\Ambience\Amb_Bed\B_Format\AMB_BED_Forest_Night_Crickets_Frogs_Short_AmbiX.wav)
Error: Failed to find speaker location; valid extensions are _fl, _fr, _fc, _lf, _sl, _sr, _bl, _br.

this is on ue4 4.19.2 with the new audio system enabled.

you can manually go in file by file and point it to the correct location and it seems to reimport (although i have not tested with obviously different source to verify this), but it would be nice to be able to select all the files in question, hit reimport and have it properly reimport the files.