Numbers in LCD custom are blurred or disappered

[gggghhhh]

i had some trouble with my stm32 project about custom LCD using HT1622. LCD display all number i want but some position number is blurred or disappeared. In addition, numbers have fewer bit 1 are almost blurry and others is ok, i don't know this error because of hardware or software. Hope somebody give me some advice. (Sorry because of bad English)