[Theme: Bridge] cannot modify links

Hi,
as admin in the website that I’m working on, I’m trying to modify specific download links in order to create Google Analytics event tracking. Specifically, I’m trying to add “onclick” events by editing “Text Block Settings” and clicking the “Text” tab (I currently use Bridge Theme). Once I save my changes and update the page, I lose all the updates and there isn’t any onclick event.

Any ideas? Thanks in advance!