The partial segments known as fmp4 (fragmented mp4) that are created by the CMAF packetizer allows you to use those segments for either LL-HLS or MPEG-DASH streams.
You do have to enable the cmafstreamingpacketizer and not just enable the LL-HLS. Did you do that @Tom Ryan?
Here a couple of docs on how to do that:
How to enable cmafstreamingpacketizer:
How to configure once it is enabled:
KEEP IN MIND!
Enabling mepgdashstreamingpacketizer and cmafstreamingpacketizer is valid but redundant, as both create fMP4 segments. If both are defined in Application.xml, Wowza Streaming Engine ignores mpegdashstreamingpacketizer and produces one set of fMP4 segments using cmafstreamingpacketizer.