Now have to manually delete notifications

Exactly same thing happened. I was playing new game plus, Hearts of Stone at level 85. Suddenly notification about save slots. Deleted local saves like it was instructed in some official MS support thread. Synced saves from cloud and now my newest save is from lvl 71, two weeks ago. Manual saves are not shown at all, only autosaves and not the latest ones. Gonna stop playing now, okay then.

I figured out how to manually delete this: Have to gain access to the hidden WindowsApps folder. I found the file folder to delete by sorting by size. Re-downloading now.

Welp, you might get a light chuckle out of this, but now I'm in the same shoes as you, DarkPaul!

I was curious about your problem, so I went ahead and took a look myself. When EA Access was free a little while back, I also partook in downloading Battlefield 4 and Hardline and giving it a play.

Since EA Access is no longer having its free time anymore, BF4 and BFHL are just sitting in my HDD taking up space.
I went ahead and deleted the BF4 base game itself without touching the DLC to get an idea of what you're experiencing. Lo and behold, it's nowhere to be found in the storage settings. Went to the store to see if I could try to "workaround"
an uninstall through the game's store page, but there was no option (it did show the DLC as "Installed" though). I at least have a big 2TB external drive, so luckily (for me) it's not a big deal right now.

Must be one bad oversight on Microsoft's part when they designed this interface.

It seems our only solution to our problem is by taking one of these avenues:

• Completely format the storage device. Reinstall your entire library.
• Find a friend who has the base game on disc. Install. Uninstall all.
• Purchase the game digitally, or buy a month's pass on EA Access. Download the base game. Uninstall all.
  

I basically shot myself in the foot (for science!), and turned out it was a bad idea. I didn't know this was an actual bug. Whoops.

Like the last guy said, let's just hope this issue gets covered in the next console update. That's about all I have left to say, sorry.

Trust me, from what I can tell we are far from alone in this. But still...science.

in the next system update they adding this so you can delete the dlcs, so just hold on until then

it will be under settings > storage