(setxkbmap) can't use "ALT_GR"/"left ALT" button after using it

hello folks
i use LXDE as i’m known
and my only solution to switch keyboard is to use setxkbmap
now after i define keyboards layouts to switch and chose ALT+Shift to switch it goes “bugged”
using the right ALT will switch the layouts
and i’m not able to write the “other” letters
help please
P.S : this is the command i use

“setxkbmap -option grp:switch,grp:alt_shift_toggle,grp_led:scroll fr,ar”

bump up rotfl!