In the middle of December 2020 my wife and I bought S20 and S20+ phones from Samsung direct. We also purchased two Samsung EVO Plus 256 GB microSDXC UHS-I U3 100 MB/s Full HD & 4K UHD Memory Card for use with the phones.
We formatted the SD Cards as exFAT and copied the data and apps from our old Samsung phones using the Samsung app.
Many of the videos and pictures taken on the old phones (Samsung S7) my wife copied across cannot be viewed on the new phone - though when they were initially copied across they could be viewed. We have both taken videos and pictures with our phones, I have stored mine on the SD card and she has stored hers on internal memory. We both get the error message "Failed to play video" An unknown error has occurred" for some but not all of the videos we have either taken with the new phone or copied across. The videos are basic FHD and in some cases , slow-motion.
This is very disappointing for newly purchased phones and cards both of which are Samsung so I am ruling out any compatibility issues.
Any help before I return them would be appreciated.