Nothing gets fixed by itself. You were obviously doing something wrong that you left out of the information you gave us.
Therefore being able to fix it by himself
Funny how people now days see someone with a problem and if they don't have the solution or it's a unknown problem so quick to jump to "your sd is probably corrupted". No advice is better than bad advice. Oh and the problem was fixed by myself, and imagine this, it wasn't my 200GB Sandisk micro sd I bought from Walmart.
Dude, I just gave an advice,I had a thumb drive corrupting stuff and Al son happened to a brand new SD card bought in a big store chain..
The thing, both devices behaved normal and didn't show any signs..stuff didn't disappear and windows didn't throw me any errors while writing..
I used that thumb drive to install windows and I couldn't finish the installation I thought it was my computer itself or a bad ISO,I tried everything to fix and nothing helped.. later I saved some mp3 on that thing drive, when playing the songs some had skips I assumed it was a bad download or I didn't copy the stuff right..
Only then I saw that something was not right, 5 minutes in h2testw and bam it was clear why I was not being able to install windows or some stuff was having random issues I thought it was my own error or my pc...
From that experience I suggest everyone to do then same.. this devices are cheap as hell its normal companies cheap the duck out (a floppy bought in the 2000s will not last as long as one bought in the 90s foe that reason)
I am just trying to do a favor to everyone to know about this..only 5 minutes (depending on the devices of course) are needed to make sure you can trust that storage unit to store your stuff...
If u have a SD card with a bad sector silently corrupting your band backup, good luck when you need it..
After that experience I can't close my eyes and blindly trust flash stuff will securely keep my important data.. just 5 minutes to say it's OK to save stuff on it