SD card deleting files automatically

Where did you get the sdcard? From the sound of it it might be a fake card.

 

Welcome to Android Forums, Gecko114!

What you're describing simply doesn't make sense. Neither Android, nor the OS it's based on, Linux, randomly or arbitrarily will delete files. Window$? Perhaps. But not Linux. It takes some form of user action for files to be deleted.

'User action' may mean something obvious, like selecting a file and pressing 'delete.' But it can also mean something less obvious, like a setting within an app.

For example, in my Ring app, I can set parameters for when/whether to delete images/videos. Like, save only up to X number of images, or delete images more than Y days old. Perhaps some app you're using has similar options--and you set them.

This makes me even more convinced of the above. I use F-Stop Gallery Pro. Here's what its help page says about how it deletes files:

"Deleting a folder will not delete the entire folder from disk unless it is completely empty. Instead, it will only delete the valid media in that folder that causes the folder to disappear from the folders view. This is done intentionally since you may have other files in the folder that you do not want to delete but isn’t shown to you by F-Stop."

Perhaps you have something similar going on.

Please let us know which media apps you're using, i.e., apps for taking/managing/viewing images and videos. If they're in the Play Store, providing links to them would be helpful.

 

A fake card--meaning its actual storage space is less than claimed--would simply not save a file if it had run out of space. I don't know how it could save it and then delete it.

 

Was it from Amazon themselves or a marketplace seller? Fake cards do sometimes get into legit supply chains, so even if it was sold by Amazon it might still be fake, but marketplace sellers are a higher risk (I've seen marketplace listings for.microsd cards with claimed capacities larger than actually exist - the vetting is not rigourous).

Best bet is to back up any data that are currently on it then test it. Some card verification apps may be able to spot if the brand is not what it should be, but the definitive test is to put it in a card reader, attach that to a PC and use a little app called h2testw: this will fill the whole card to its declared capacity and then check that the data can be read back correctly. If the card claims to have a large capacity this can take a long time, but it's a test that can't be cheated or tricked.