emoji not stored on mysql

i have problem with this guys...... on spool table i can't store emoji

[error] <0.765.0>@ejabberd_odbc:outer_transaction:444 SQL transaction restarts exceeded
** Restarts: 10
** Last abort reason: "#HY000Incorrect string value: '\\xF0\\x9F\\x98\\x98\\xF0\\x9F...' for column 'xml' at row 1"
** Stacktrace: [{ejabberd_odbc,sql_query_t,1,[{file,"src/ejabberd_odbc.erl"},{line,167}]},{lists,foreach,2,[{file,"lists.erl"},{line,1337}]},{ejabberd_odbc,outer_transaction,3,[{file,"src/ejabberd_odbc.erl"},{line,437}]},{ejabberd_odbc,run_sql_cmd,4,[{file,"src/ejabberd_odbc.erl"},{line,374}]},{p1_fsm,handle_msg,10,[{file,"src/p1_fsm.erl"},{line,582}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,240}]}]
** When State == {state,<0.771.0>,mysql,30000,<<"estjava.id">>,1000,{0,{[],[]}}}

so, what is the problem? my sql table i set to utf8mb4, but can't solving the problem.....