Here are some possible reasons why you can't save GIFs on your iPhone with iOS 14:
You may be using an older version of iOS. Apple releases updates for iOS on a regular basis, and these updates often include bug fixes and performance improvements. Make sure you have the latest version of iOS installed on your device.
The GIF you're trying to save may be corrupt. If you're trying to save a GIF that's been damaged or corrupted, it may not save properly. Try saving a different GIF to see if that works.
There may be a problem with your internet connection. If you're having trouble saving GIFs from the internet, make sure you have a strong and stable internet connection.
Have you tried this guide? - https://cult.technology/how-to-save-gifs-on-iphone/