Cassandra-4-Update: Multiple Schema Versions

after upgrading our first node, it has a different schema version (according to node tool describe cluster). This caused Spark Jobs to hang, because of reoccurring "schema agreement not reached" by metadata.SchemaAgreementChecker. Is this different schema version by purpose? Will the problem being gone after updating all nodes (first update all nodes, then run upgrade sstables)? Can Spark Jobs configured to overcome the hang-up? Many thanks in advance. Best Regards, Sven