Something to keep in mind is the Gallery app is just a basic photo manager. It's often the default media manager app on most phones, a primary aspect to any 'default' app being it's by-design meant to have basic features that appeal to the most common needs. So in most situations, there are photos and videos stored in different locations in your mobile device -- i.e. the DCIM/Photos/Pictures folder, the Downloads folder, some apps opt to use their own folders, and all of them may reside in your devices internal storage or a microSD card storage. The Gallery app simply scans those different media folders, and then displays what it finds.
In your query, the Gallery app on your Vivo is apparently having issues in finding and indexing all your photos and such. Using Clear data on the Gallery app would have returned the app back to its original default settings so since the app is having problems finding all your photos it would appear you need to a) access just where all your photos are being stored and then b) go into the Gallery app's settings menu so it will detect those folders. A good way to do file and folder management on your phone is to install a file manager app. I'll just recommend an app like 'Explorer' from Speed Software. It has a good feature set, free with no ads. But there are plenty of file manager apps on the Play Store to choose from. Basically they're all functionally similar, the biggest differences being the user interfaces so pick the one you're most comfortable using.
https://play.google.com/store/apps/...e.explorer&hl=en_US&gl=US&showAllReviews=true
Anyway, a file manager app gives a visual way to access just where all your photos might be located. At one time, the DCIM folder (Digital Camera IMages) used to be an industry default location to store photos and videos, but now the situation is much more convoluted as different phones may still being using DCIM, or it might be a Photos folder, or it might be a Pictures folder. Check the settings menu in your Camera app to see where it's set to store photos by default. And don't forget that other apps will be likely to use different folders and locations. Your browser app will probably use a 'Downloads' folder for its default, as do a lot of text messaging apps. Once you have a handle on all the folders where your photo library might be stored in, add those to the Gallery app's detection folders.
If the Gallery app on your Vivo doesn't allow you to add/alter which folders it auto-scans, you might want to just stop using it and install a third-party app instead. The Simple Gallery Pro app from Simple Mobile Tools is a lot more versatile than the Gallery app. It has a very extensive Settings menu with more options (alter the user interface, set folders to scan/ignore, etc.) and it's an Open Source app that's free with no ads (no ties to corporate influence or oversight).
https://play.google.com/store/apps/details?id=com.simplemobiletools.gallery.pro&hl=en_US&gl=US
Another option is to install the Google Photos app:
https://play.google.com/store/apps/details?id=com.google.android.apps.photos&hl=en_US&gl=US
It's not as customizable as Simple Gallery, and if you're averse to Google oversight this is
not an app that appeals to privacy advocates. But the app does include a really handy 'backup and sync' function. So as a photo library manager app it's OK, but that automatic backup feature is a big plus point. It uploads your entire photo library into your online Google account, enabling you to access all your photos both on your phone or going to
https://photos.google.com on a remote desktop/laptop.
Facebook
Twitter
Instagram