JackH828,
Let's also make sure that your iPhone is all up to date using the steps below:
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see two software update options available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
You can also find those steps in this resource: Update your iPhone, iPad, or iPod touch - Apple Support Updating should help to further isolate a potential software conflict.
If your iPhone is already up to date, does that persist after restarting? Restart your iPhone - Apple Support
Also, are you using the Apple Lightning to SD Card Camera Reader, or an adapter from another manufacturer? Lightning to SD Card Camera Reader — Apple - Apple
Let us know, and we'll keep moving forward from there.