I cut coffee for a year or so 10 years ago due to stomach issues, then slowly added fancy espresso drinks back, figuring that if I was only having coffee once a week, it might as well be fancy. I don’t seem to have stomach issues now with 1-2 lattes/cappuccinos a day.
Maybe it’s unrelated, all in my head, better beans, or the 3-4 oz of whole milk, but maybe give espresso drinks a try if you haven’t?
It’s likely a better roasting process and fresher beans. Large scale coffee roasters produce burnt, more acidic beans with chemicals added during the process.