I was a professional chemist for around ~7 and love to cook. My suggestion is to stop expecting precision with an imprecise and natural product like cooking. Are your lemons larger? They also might be sweeter, tarter, juicer etc. than others. Same thing with teaspoons. The spices you are using may be more or less concentrated than who wrote it.

Lean into the uncertainty and be free. Double or even triple spices to see if you like it. Measure with your heart