Comments - Unsupported command in prepared statement using the new JDBC Driver 3.0.3
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With batches, driver use a BULK dedicated command that has a known issue with INSERT ... SELECT. See https://jira.mariadb.org/browse/MDEV-26673
So you can either disable BULK setting option useBulkStmts=false. or rewrite this specific part to not using batches.
The reason of why that differ compared to 2.7 is that now, when server support it, PREPARE + EXECUTE/BULK are send 'pipelining', permitting better performance. The only bad thing is that when PREPARE fails, there cannot be a workaround using a client prepared statement replacement.