iOS version should not make any difference. Did you update Opera Touch to latest version (2.5.3)?
If you have update Touch and it still fails you can try this workaround:
Its for existing wallets with assets and something that worked prior to the latest fix (Note: it requires reinstall and backup phrase):
Open settings, in Opera Touch for iOS
Scroll to Crypto section and open 'Backup phrase'
Tap 'Unlock' and copy/save the backup phrase in a secure place
Uninstall and reinstall Opera Touch for iOS
After installation, open settings and activate wallet
Select "Restore from Backup", sync with desktop and enter the backup phrase you saved previously to restore all assets.
Open settings->Crypto and Connect to computer and follow instructions to sync.