Hello kkgirl28,
If uninstalling and reinstalling the application does not help, check to make sure you have the correct region set up for your iPhone next. The steps here will help:
1. Go to Settings 
> General > Language & Region.
2. Set the following:
• The language for iPhone
• The region
• The calendar format
• The temperature unit (Celsius or Fahrenheit)
• The measurement system (metric, U.S., or UK)
• The first day of the week
• Live Text (text you can select in images to copy or take action on)
3. To add another language and keyboard to your iPhone, tap Add Language, then select a language.
Change the language and region on iPhone - Apple Support
If you have the correct region set up for your iPhone, next check the country set up for your Apple ID. This resource will show you how: Change your Apple ID country or region - Apple Support
Should this persist, it's possible the application was set up using the country you were visiting. If that's the case, try reaching out to the app developer for guidance on changing this back. To locate the app developer contact information, follow this link: How to contact an app developer - Apple Support
All the best.
