Make sure that all shipping profiles have the 150€ + free shipping rate. When you check each shipping profile, you'll need to make sure each shipping zone has the 150€ + free shipping rate. For example, here's a screenshot from my test store of a general profile, with more three different zones. Each zone must have this shipping rate for it to apply at the checkout:
Let me know how checking your settings goes. If you're still having troubles, if you're willing to share screenshots of your shipping rates it would be helpful for troubleshooting.
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