Google Tag Manager stops tracking any activity after proceeding to checkout

I have tried different themes with each installed google tag manager code, but with all themes, google tag manager doesn’t track any activity after proceeding to checkout. This means that there is also nothing showing up in the summary tab (GTM preview mode) and the preview mode also disconnects once proceeding to checkout. My website URL is: glymmerclothing.com

Does anyone know how to solve this?

Hello,

thanks for your interest in solving my problem, I’m definitely open for a discussion, What would you think is the next step in order to solve this problem?

Hello,

have you found any reason why this happens? Its the same for me..