It seems like on initial page load we set the User ID and it is sent to Piwik. However, after that the future events sent to piwik have some randomly generated hex uid instead of the one we set. This results in the user's session not being tracked properly.
My workaround is to use custom variables for the User ID instead.
It seems like on initial page load we set the User ID and it is sent to Piwik. However, after that the future events sent to piwik have some randomly generated hex uid instead of the one we set. This results in the user's session not being tracked properly.
My workaround is to use custom variables for the User ID instead.