Most display issues in your Jaxx wallet can be solved by a cache reset.
First, secure your backup phrase (Menu > Tools > Backup Wallet > View Backup Phrase). Make sure you have this phrase written down as it essentially holds all of your funds.
Now, perform a cache reset (Menu > Settings > Reset Jaxx Cache). This will not disrupt your funds, but will reset your wallet preferences such as your preferred choice of currency display.
If you have set up a security PIN, the cache reset will not reset the PIN or the PIN feature.
When in doubt, it is always helpful to perform a cache reset.