Hi! I'm sorry to hear that you're having issues with your Tecno Pova 3's fingerprint lock after performing a software update. Here are a few things you can try to resolve the issue:
1. Clear the cache of the fingerprint application: Go to Settings > Apps > Fingerprint > Storage > Clear Cache. Restart your phone and check if the fingerprint lock is working.
2. Remove and re-add the fingerprint: Go to Settings > Security > Fingerprint > Fingerprint Management > Delete. Then, follow the steps to add your fingerprint again.
3. Check for software updates: Make sure your phone is running the latest software version. Go to Settings > About Phone > System Update > Check for Updates.
4. Perform a factory reset: This should be a last resort, but if all else fails, you may need to perform a factory reset. Note that this will erase all data on your phone, so make sure to back up your important files before doing this. Go to Settings > System > Backup and Reset > Factory Data Reset.
If none of these steps work, it may be a hardware issue and you should contact Tecno customer support or bring your phone to an authorized service center for repair.