I have also had problems with storage zones. We experienced multiple periods of timeouts, super long TTFB, and 5xx responses. A ticket was opened (#136096) about the TTFB issue with full headers/curl output with an offer to supply any further useful information, but the response of "can you confirm this is no longer happening?" the following day discouraged me from further time spent there.

To this day US PoPs are still pulling from EU storage servers (our storage zone is in NY, replicated in DE).

  < Server: BunnyCDN-IL1-718
  < CDN-RequestCountryCode: US
  < CDN-EdgeStorageId: 617
  < CDN-StorageServer: DE-51

We've since moved away from Bunny, but if there's anything I can do to help improve this situation I'd be happy to do it because it is otherwise a fantastic product for the price.