Auto correct not working with all contact text messages

Why does my auto correct change "i" to "I" with some contacts and not others? I can be texting multiple different people at the same time (different message threads) and in one message it will auto correct then I'll switch to another text message with a different contact and it won't auto correct. It leaves the I as lowercase and doesn't correct it to uppercase. If I type the contact's name, it will show their contact photo with name. In the same message, if I type "i" it will show the same contact photo with a capital "I" that I need to select for it to auto correct the lowercase i to capital I.

With the update if you are typing the contact's name it will show their picture in the autocorrect section at the top of the keyboard so you can have their name show bolded in the text. For some reason this is only happening with random contacts.