The guy on YouTube called high intensity health is a keto diet evangelist who wears a real time glucose monitor to study more closely what’s going on biologically with ketosis and blood sugar. He’s reported that being in stressful situations, like being late at the airport, can spike your glucose even when you’re in ketosis and kick you out of ketosis. I’ve experienced this too with the resurgence of inflammatory symptoms that are usually gotten rid of by ketosis.