Uninitialized scalar field
The field will contain an arbitrary value left over from earlier computations. A scalar field is not initialized by the constructor
/src/mongo/db/repl/tenant_migration_recipient_service.h:581: UNINIT_CTOR 121257 Class member declaration for "_backupCursorId".
/src/mongo/db/repl/tenant_migration_recipient_service.cpp:385: UNINIT_CTOR 121257 Non-static class member "_backupCursorId" is not initialized in this constructor nor in any functions that it calls.