Hello, thank you for your answer and your help,
I have just updated to 6.0.2 but unfortunately the issue remains the same, as soon as I add the second product, I get this message on the cart :
Notice: Undefined index: id in /home/cp1019618p24/public_html/wp-content/plugins/tier-pricing-table/src/Addons/GlobalTieredPricing/GlobalTieredPricingCartManager.php on line 48
Your help is appreciated,
Regards
Vincent