@mustaasam.saleem I use WordPress with WooCommerce then enable WPMU.
@hassam.sattar Thank you for looking into this. Can we use wildcard URLs to exclude these WooCommerce page.
Also, I think this issue is also related to Breeze (wp-content/breeze-config/breeze-config.php).
Without any setting on Varnish rule, if I go to Breeze setting on woocommerce-112688-329520.cloudwaysapps.com/wc and click save, the breeze-config.php will be override with exclude URL that contain /cart, /my-account, /checkout and the site will works fine.
Then if I go to Breeze setting on woocommerce-112688-329520.cloudwaysapps.com/no-wc (no WooCommerce on this site) and click save, the breeze-config.php will be override without exclude URL that contain /cart, /my-account, /checkout and all WooCommerce sites in WPMU network won't work fine.
For conclusion, I think the cause of this issue is all sites in WPMU network use the same "wp-content/breeze-config/breeze-config.php". Each site should have their own breeze-config.php