When it is not possible to to obtain the global read lock then Debezium

1. obtains list of tables
2. filter out whitelisted tables
3. lock whitelisted tables
4. snapshot schema either only whitelisted tables or all tables depending on setting
5. the step above fails when schema of non-whitelisted table is taken as MySQL prevents access to non-locked table when another table is locked

As workaround - use database.history.store.only.monitored.tables.ddl set to true.

The final solution

• either whitelisted tables have to be snapshotted fully then tables unlocked and schema of non-whitelisted tables should be taken
• or two database connections are established - one used for snapshotting of schema of non-whitelisted tables