As far as I know Hootsuite uses our API to retrieve our stats. As such, the stats should be the same.
Our records do show a gap in data between the end of June and the 18th of July, as well as between the 9th and the 25th of July, which would probably explain the discrepancy you're seeing between the two reports.
There is unfortunately nothing I can do to change this, as we can not retro-actively retrieve follower numbers. As I do not know what the Hootsuite report looks like, I also can't say whether it's "fixable".