incorrect value for charset utf8mb4 and longtext column with multibyte unicode characters

When column of type longtext contains multibyte unicode characters ODBC driver does not return correct data - for varchar field it works ok...

To reproduce:
//init DB stuff (i use utf8mb4_czech_ci collation)
create table test_table (s_col varchar(100), m_col longtext);
insert into test_table values('🤣👍','🤣👍');

//test in VBS file
set conn=CreateObject("ADODB.Connection")
conn.open "DRIVER=

;SERVER=...;DATABASE=...;UID=...;PWD=...; OPTION=3;charset=utf8mb4;"
set rs=conn.execute("select s_col, m_col from test_table")
s=rs("s_col").value
MsgBox "S (" & typename(s) &") " & s
s=rs("m_col").value
MsgBox "M (" & typename(s) &") " & s
rs.close
set rs=nothing
conn.close
set conn = nothing

Expected behaviour

• both S and M messages should show (String) + unicode emojis

What happens

• S - shows (String) + unicode emojis
• M - shows (Empty)

when charset is set to utf8 both columns returns ??