Hi, FC from a German living in Thailand here. I’ve noticed that you tend to shift gears rather quickly, without fully utilizing the tachometer and the RPM range that sport bikes are designed to enjoy. In general, engines-especially performance engines-function better at higher RPMs. Low RPMs put unnecessary stress on the engine. It’s similar to riding a regular bicycle in high gear but at a slow pace-it’s much more difficult, right? The same principle applies to motorbikes. Perhaps this is the reason behind your bike’s recent issue? There’s a quote I really like: "You paid for the whole tachometer, so use the whole tachometer." Low RPM, high gear, and low speed are all key indicators of the spark plug issue that others have already mentioned.