Kindly do self troubleshoot as per below and try to relogin after:
1) Logout and re-Login App- if error still persisting proceed to next step
2) Uninstall and re-install App - if error still persisting proceed to next step
3) Update the app
Open Google Play -> My apps & games - > Touch ‘n Go eWallet app (Update the app is there is any new update)
4) Line connectivity
Launch your internet browser, type www.google.com and tap Go. If the page fails to load, you may have internet connectivity issues.
5) Clear Cache/Data/Storage (the term differs across phone models) > ‘Allow’ all permission
Open Settings, tap Apps and look for Touch ‘n Go eWallet app. Scroll to the bottom. Choose STORAGE and tap the CLEAR CACHE button.