You should be getting the error message
[2024-04-09T13:39:00,820][WARN ][logstash.filters.mutate ][main][8bc32b302327baed89200cd426ab77a8c3d27a62890a06a7d84f32da3b340613] Exception caught while applying mutate filter {:exception=>"Could not set field 'userType' on object '%{[individual][user]}' to value 'SUBSCRIBER'.This is probably due to trying to set a field like [foo][bar] = someValuewhen [foo] is not either a map or a string"}
Your first mutate sets [user] to be a string, but your second mutate tries to make it an object with nested fields. You cannot do that. See this thread.