Google Analytics is not tracking traffic sources correctly

These are the most common causes for Google Universal Analytics not tracking traffic sources correctly, and the recommended solutions:

Problem: you use links in your web site. Since these links are not "decorated" by Google Analytics, even if they redirect the browser back to the booking page in your web site, Google Analyticsthinks this is a new "entry" to your site, and it loses the source.
Solution: Do not use links in your site if you want traffic source to be kept. You can use a widget code that corresponds to any direct link, place that widget in a page of your web site, and use a link to that page instead of the link
Alternative solution: you may try adding to your Google Analytics account Referral Exclusion List. 

Problem: you use a property ID in Bookeo that is different from the one in your booking page or in your site. 
Solution: make sure that the property IDs in your web site and Bookeo match.

Problem: you have removed your own domain name from Google Analytics's Referral Exclusion List. Google adds it by default, but you may have removed it in error.
Solution: double check that your domain name (without "www.") is included in your Referral Exclusion List: 

Problem: you have multiple copies of the Google Analytics tracking code in your web site
Solution: check the source code of the page in your browser (open the page in the browser, right-click on it and select "View source"), and search for multiple copies of the GA code. If there is more than one, remove duplicates.

Still not tracking traffic sources correctly?

Although normally not necessary, you may still need to add special code to your Google Analytics code in your web site, to "aid" Analytics to identify sessions flow.

Simply edit the Google Universal Analytics code that is included in every page of your site, and add the parts in red:
ga('create', 'UA-12345678-1', 'auto', {'allowLinker': true});
ga('require', 'linker');
ga('linker:autoLink', [''] );
ga('send', 'pageview');

Remember this change must be applied to every page of your web site.