Try going to Settings > App and click "Refresh now" to clear caches. If you have an account, sign out and back in to trigger a fresh sync. If data was lost, check if you have a backup JSON file you can import.
Go to Settings > App > Market Data and click "Re-fetch market data". This clears the cached prices and fetches fresh ones. Prices update automatically but can sometimes lag behind.
Charts need at least 2 confirmed months of data to show trends. Make sure you have confirmed (not just entered) your monthly balances. Unconfirmed months show with a yellow dot on the Balance page.
Still stuck? Open the app and use the help button in the corner to reach a human.