Syntax error with federeted_pushdown=ON and using SOME operator

Issue:

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With federated_pushdown=ON , query throws syntax error
Note: With OFF , query executes fine.

MariaDB [m8]> UPDATE M AS OUTR1, M AS OUTR2 SET OUTR1.a = NULL WHERE OUTR1.a < SOME ( SELECT a FROM M);
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '<nop>(`m8`.`OUTR1`.`a` < any (select `m8`.`M`.`a` from `m8`.`M`))' at line 1

Version used:

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Debug build
Branch : 13.2-MDEV-41243-fedx-pushdown-assert-for-upd-del-prepared-stmts
commit: e7d83013b31c4cc97a0003a0e58b707d94cba042
Version : 13.1.0

How to repeat:

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Slave:

create table M( a int);

Master: Start server with federated engine enabled

create table M(a int)  ENGINE="FEDERATED" CONNECTION='mysql://u3@127.0.0.1:3306/m8/M';

set global federated_pushdown=ON;

UPDATE M AS OUTR1, M AS OUTR2 SET OUTR1.a = NULL WHERE OUTR1.a < SOME ( SELECT a  FROM M);