I should've paid more attention when setting up the index. I forgot to add field analyzers for each field. The multilist fields were getting indexed with a different analyzer instead of the standard analyzer. I added this to my config section for field crawls and my query started working
<fieldTypes hint="raw:AddFieldTypes">
<!-- Text fields need to be tokenized -->
<fieldType name="single-line text" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="multi-line text" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="word document" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="html" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="rich text" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="memo" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="text" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<!-- Multilist based fields need to be tokenized to support search of multiple values -->
<fieldType name="multilist" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="treelist" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="treelistex" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<fieldType name="checklist" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
<!-- Legacy tree list field from ver. 5.3 -->
<fieldType name="tree list" storageType="NO" indexType="TOKENIZED" vectorType="NO" boost="1f" />
</fieldTypes>