Why Wont My Pictures Download From Iphone

Messages showing “Tap to Download” instead of images. To download), I cannot view any photos from Charlie (I get a tap to download box, but it's stuck at 0 bytes). If I view the conversation on another device (e.g. A MacBook), I see the image just fine. Why is this happening, and what can I do to resolve this issue on my iPhone?

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So I have looked on the interwebs already for a solution to this but cannot find one anywhere. I don't have the issue of the phone being locked or anything like that. The problem is a little more frustrating. I have around 300 photos on my iPhone and I can see them on my iphone. However, when I plug it into my pc or mac, I can only see around 30.
So I downloaded a software called Syncios, which just allows you to transfer photos and videos from your phone to the pc. The good news, in Syncios I can see all my photos. The bad news, even though it allows me to select and export all the photos, only 30 still transfer.
What is going on here? Can anyone help please, it's driving me crazy and the iPhone won't let me take anymore photos until I've offloaded what I have on there.
Thank you in advance for any help offered.