bug with del() about datajoint-matlab HOT 6 CLOSED

%{
duty_roaster_date:  date       # date from which this assignment is valid.
----- 
(monday_duty)    -> lab.User(user_id)
(tuesday_duty)   -> lab.User(user_id)
(wednesday_duty) -> lab.User(user_id)
.
.
%}

lab.DutyRoaster

    DUTY_ROASTER_DATE       monday_duty         tuesday_duty        wednesday_duty      ...   
    _________________    _________________    _________________    _________________    ...

     {'2021-03-10'}      {'jrw10'        }    {'baptista'     }    {'jrw10'        }    ...
     {'2021-03-11'}      {'testtech_del1'}    {'testtech_del2'}    {'testtech_del1'}    ...

key.user_id = 'testtech_del1'
del(lab.User & key)

ABOUT TO DELETE:
       1 tuples from `u19_lab`.`user` (manual)
       2 tuples from `u19_lab`.`duty_roaster` (manual)

%{
user_id: varchar(32)
%}

classdef User < dj.Manual
end

%{
duty_date:  date
----- 
(duty_first)    -> lab.User(user_id)
(duty_second)    -> lab.User(user_id)
%}

classdef Duty < dj.Manual
end

users = [{'user0'
          'user1'
          'user2'}]

insert(lab.User, users)

duty = [{'2020-01-01','user0','user1'},
        {'2020-12-31','user1','user2'}]

insert(lab.Duty, duty)

lab.User()

     USER_ID 
    _________

    {'user0'}
    {'user1'}
    {'user2'}

lab.Duty()

      DUTY_DATE       duty_first    duty_second
    ______________    __________    ___________

    {'2020-01-01'}    {'user0'}      {'user1'} 
    {'2020-12-31'}    {'user1'}      {'user2'} 

key.user_id = 'user0'
del(lab.User & key)

ABOUT TO DELETE:
       1 tuples from `kabilar_lab`.`user` (manual)
       2 tuples from `kabilar_lab`.`duty` (manual)

Proceed to delete? (yes/no) > yes
Deleting from lab.Duty
Deleting from lab.User
committed


lab.Duty()
0 tuples

key.user_id = 'user0';
del(lab.User & key)

Error using  ~ 
Too many input arguments.

Error in dj.Relvar/del (line 95)
                            if ~fks.aliased