SP list attachments added in SP and mobile PowerApps do not open in the mobile (ios) app. Same items do open in SP and browser PowerApp. Seleting the item in the mobile app brings up Apple's menu to copy to another location, another app or to print - no open to open or view.
Is there a way to open list attachments, or is this a bug in the mobile app?
Do you mean the attachment can not be viewed in mobile PowerApps?
That is not a bug. When we select the attachment in the form, the attachment would be downloaded to your device, both mobile and brower PowerApps are. Also, I'm afarid there is no way to view the attachments directly in mobile powerapps.
You can choose to save image or save to files in Apple menu, and the attachment will be store in your phone, you can be easy to view it.