There appears to be an issue with pjax and offcanvas elements. I have a standard offcanvas element with links inside the header template. When the page is loaded normally the offcanvas is able to be triggered by the toggle element but once I click on one of the links and go to another page I can’t trigger the offcanvas element unless I refresh the page. It appears to have something to do with pjax because moment I switched it off the offcanvas worked again. I don’t actually need pjax for this project so not sure why I switched it on but haven’t changed any of the settings on it yet so everything is still default. I’m on a local dev site so I don’t have a link but just thought I would point it out in case it’s a bug that you’re able to replicate and fix.
Hey! 
Just tried it. Pjax works wunderfully with the Bricks native Offcanvas element here. Do you see any javascript errors in the console? Or are you using the Offcanvas from BricksExtras?