Number of indexes inside InnoDB differs from that defined in MariaDB after altering table with vector key

--source include/have_innodb.inc

CREATE TABLE t (v BLOB NOT NULL, VECTOR INDEX (v)) row_format=compressed ENGINE=InnoDB;

ALTER TABLE t ADD f INT;

INSERT INTO t VALUES (x'00000000',1);

# Cleanup

DROP TABLE t;

INSERT INTO t VALUES (x'00000000',1);

Warnings:

Warning	1082	InnoDB: Table test/t contains 1 indexes inside InnoDB, which is different from the number of indexes 0 defined in the MariaDB