iPhone 6 no longer lets me attach pictures to imessage or sms unless it is one of 10 most recent picutres taken

Hi there,

I'm no longer able to attach photos to my messages unless it is one of my 12 most recent pictures or so.

I have an iPhone 6 and running iOS 9.3.1

I click the camera icon and the pictures load (I have storage optimization on) and I press "choose" and nothing loads in my message box. I have 1GB of free storage left on my 16GB phone so I don't think its storage space issue (Ive had less storage before and have been able to send photos). I have a feeling it might have to do with the new picture storage optimization feature but unclear. Would love to be able to keep this function on as it helps a lot with storage space but not being able to send pictures from more than a day ago is very frustrating. I have reset network settings .

Anyone else having this problem? or know how to fix?