As mentioned previously, the ideal forum for this sort of report is the public issue tracker. I see you've already reported an issue as
Issue 96. Please continue to use that report for investigation. There are some questions there that still need to be answered to move the investigation forward and be sure to provide a
HAR file as suggested by Nick to help identify possible Developers Console issues.
Fabio, I would recommend that you star the linked public issue created by Oscar for support and updates. You could also attach your HAR file there as well to further help the investigation.
Thanks for your patience!
Nick (different Nick)