shukler loader not working

my shulker loader not working everytime its full i have to manually break the redstone on the redstone block to replace the shulker,

https://preview.redd.it/3o6wvtzu5w4g1.png?width=3420&format=png&auto=webp&s=cdc42c3773244fd8d2034cb954adb7bcc5634a41