You can go into your phone settings and change the size that is used for sharing or other purposes. I'll try and find it in the morning on my iPad and then look at my wife's iPhone to see where it's found at. The forum settings are very liberal and at the high end of what you'd commonly find in the wild west of the internet.
This issue just cropped up in another sub forum here https://stormtrack.org/community/threads/file-size.30620/. I don’t ever have problems myself but people and the different equipment they use introduces so many variables that it’s hard to offer any advice unless a complete description of what happened along with screen shots are provided so there is a place to start.