Check and Home Settings

[Pierre F8APV]

Hello everybody.
I see a strange behavior of "Check" key when I set some value to Digit Grouping in home settings...
For example, if Digit grouping is 123456,789, Check give syntax error with this test program :
(Cursor position just after the 'a' line 4)

If I set Digit grouping to 123456.789 no error... ?

EXPORT test()
BEGIN
local a;
input({{a,[0],{15,30,0}}});
END;