I know it's really weird but I think it might be because it's made by/for the shop Specifically. Can't add the picture from my phone but it's 166mg/10ml for sure
If you added two of those to 70 ml of juice, you'll have 90 ml of 3.7 mg/ml juice. That would be reasonable for a DL device, very low for an MTL device and exceedingly low for a pod, which is where the Myle fits. I'm not surprised you're not getting results. Unfortunately, the EU's TPD doesn't really take account of different styles of vaping.
Given the nicotine concentration limits you're dealing with, your best option might be to look at a more powerful device. Recommended nicotine levels depend on the device you're using and how much you used to smoke, but as a rough guide you'd usually want 9 - 20 mg/ml for an MTL device and 3 - 6 mg/ml for DL.
I really hope you can find something that works for you. Good luck!