UPDATE Jan 1, 2020: this issue is now resolved
for details see Changelog v0.28.4 https://github.com/storj/storj/releases/tag/v0.28.4
Warning: Garbage collection is interfering with free space calculation. If your storage node is full and executes garbage collection it might accept more pieces than it has free space, leading nodes to become disqualified. We are working on a fix. Please reduce your allocated size to make sure the storage node does not run into a crash.