Add DLC's and save file data after purchase?

That's why I said 1 save, and 1 piece of DLC. 1 save and 1 DLC does not equal 6GB of data. If it works with one DLC then try with another after that.

Sounds like there is some conflict with the data and disc... This happened to my cousin, and his solution was to delete the entire SR3 save file, then redownload all the DLC and install the game data. If then worked fine.

Some DLC (most) will render a prior Game Save File inoperable if the DLC is not present. That is even if the DLC Content was not played, it will still be present on the Save File itself.

The Update itself should not persist after the Cache has been cleared along with any possible File Saved to the HDD. Some new Games Write the Update to the HDD User Partition and not the Cache itself. Have you checked for any new
Save File and what Game is it?

That is because the data is saved to your phone and once the game is deleted on there, that will include the files. To avoid this feom happenning again, just back up your data first from your phone's file manager. Go to the game folders and copy the data, save it to another folder so you can just copy it back to the game files after reinstalling.

Unfortunately, simply re-downloading the files doesn't do anything. The problem doesn't appear to be with the files themselves but rather the game's ability to read them. Other games have no issue with their DLC; it's isolated to borderlands 2. Furthermore,
even after immediately downloading a file, it's still listed as "not downloaded". This hasn't changed regardless of whether I cleared the data from the system first or simply saved over the file.