Unfortunately, Jawbone's system has gone down, and is no longer sending any data to Stridekick when you sync.
Though they have yet to make an official announcement it seems likely that the company has closed. Jawbone has been liquidating their assets since 2017.
We’re very sorry we can no longer sync steps from Jawbone. Please visit the Stridekick 101 section of the Help Center for other syncing options: