Synchronize Browser favorites was activated.
I deactivated it and all is OK.
I bought Cookie (5.9.4) from your Website an use it on OS X 10.11.6.
When I activate Firefox in Cookie and start Firefox, Cookie will load 750 Cookies and declares them as favorites. When I deactivate them in Cookie, it will load them again when I open Firefox again.
I deleted all Cookies in Firefox and I deleted the Firefox Cookies in User–> Library–>Application Support–>Firefox–>Profiles
What can I do?
Right now I have disabled Firefox in Cookie.