There are many reasons which may cause Oppo phone data loss:
Viruses and malwares are few of the major reasons that can cause file deletion on any Android operating device. So take appropriate preventive measures to keep the phone virus / malware-free by using any reliable antivirus app
Receiving files and other contents from other gadgets that may are infected with viruses and malicious softwares can harm your phone too causing data loss. So avoid receiving any files or folders from sources you do not trust
Attaching your Oppo device on different platforms frequently such as with local media players, computers, music systems in cars, etc. can cause data store on your device to get deleted. So be cautious not to connect your device frequently
Bugs in the Oppo device firmware or other softwares that have the permission to read / write data on the device can be a cause to erase or corrupt any data on it. Try to keep your device in good condition by avoiding needless actions such as rooting the device, etc.
There are sometimes conditions that are simply inescapable such as unknown errors that can result in data deletion leaving you no other option but to restore Oppo smartphone in order to get back deleted or lost contents
The best way to recover deleted files from Oppo samrtphone is to try this solution:
The Oppo phone data recovery software is easy to use. You can recover deleted files and lost data from Oppo Android phones, incuding Oppo F3, A37, A57, F1s, F3 Plus, A71, F1, R11, Neo 7, A77, A39, F1 Plus, R9s, R11 Plus, Neo 5, R1001 Joy, Find 5, Neo 3.
Here's the steps to recover deleted files from Oppo phone
Step 1: Connect your Oppo Smartphone to a Windows system and wait for the connection to get established.
Step 2: Select Oppo Smartphone drive from where you wish to perform data recovery and click “Next” button to begin scanning process.
Step 3: List of recoverable files will be displayed on completion of the scanning process. Select files you want to recover, and then press "Recover" button to save them.