My coworker sent me this error which is weird and never happened before

Error executing Cypher command:
UNWIND $batch as row
MATCH (a) WHERE ID(a) = row.source_id
MATCH (b) WHERE ID(b) = row.target_id
MERGE (a)-[r:`causal_action`{chunk: row.features.chunk}]->(b)
RETURN a, b, r 

-> Not a JSON Object: []

When he restarted the app, which executes all queries with root account he had this error :

Exception: ('java.lang.SecurityException', "User 'root' is not allowed to create records on type 'causal_action'")

Which is caused by the execution of this cypher query (we can't be sure of the exact query because it's built on runtime)

Starts with :

            UNWIND $batch as row
            MATCH (a) WHERE ID(a) = row.source_id
            MATCH (b) WHERE ID(b) = row.target_id

And ends by either :

"MERGE (a)-[r:`{relation_type}`]->(b)"

or

f'MERGE (a)-[r:`{relation_type}`{{{features_as_properties}}}]->(b)'

(it's python strings, not the literal query for the ending)

Right now I don't have the bandwidth to fix it, if there is anything OBVIOUS that can cause this, it's fine, else, tell me so and i'll try to find a way to reproduce the issue