Each version of this integration matches a specific build of Unreal Engine 4. Here is what has changed between the 2018.1.8.6907.1293 and the 2018.1.9.6942.1328 release of the integration (in addition to upgrading to the new Unreal build).

Unreal Engine 4.19/4.20/4.21/4.22 - Wwise 2018.1.9.6942.1328

• WG-43403 You're now prevented from adding an AkAudioEvent to a Niagara timeline using drag and drop.
• WG-43943 Fixed: Spatial Audio: Distance between the emitter and listener is computed incorrectly when comparing against the "Diffraction Max Path Length" parameter, causing geometric diffraction to not be calculated at the correct radius.
• WG-44118 Fixed Load Bank and Unload Bank blueprint node that didn't resolve properly when using the string argument.