Most Arabic fonts not being rendered/painted properly

Hello,

I tried many Arabic fonts that turned out to be really awkward. Some letters were missing, letters were not connected properly. The only font that sort of works is Amiri and even that has a few letters that are not corrected properly. Keep in mind this is after getting base64 of each font and adding it. Take font Cairo for example, as I type

ولما كان تناسي حقوق الإنسان وازدراؤها قد أفضيا إلى أعمال همجية

I get لما كا تناسي حقو لإنسا ها قد فضيا لى عما همجية

As shown in the picture

I am an Arabic speaker, so I know if letters are missing or not. I will try to solve this issue.

Thanks