The 97% figure matches what we measure on that volume: about 4.8 GB used of its 5 GB size. That figure counts the storage blocks allocated on disk, not the size of the files you can see, so it can read higher than du or df inside the container. That is especially true after large deletes or frequent file rewrites. Some of that space is given back on its own over time, but the figure always settles somewhat above what df shows. We don't run a manual reclaim on request.

5 GB is also the largest volume size your current plan allows, so the volume can't be resized any bigger on this plan.