There is a condition called euglycemic ketoacidosis (EDKA) that presents with DKA symptoms, but with normal blood sugars. If you are doing low carb, keto eating then ketones up to 3.0 are not uncommon in nutritional ketosis. I have found that occasionally I've had readings as high as 5.0 on a keto diet but typically when I've eaten a lot of protein and not been as hydrated as I should be.
Have you experienced DKA before? Make sure you are hydrated, keep checking your ketones. If you start feeling unwell, brain fog or nauseous you may want to call 111. If you find yourself vomiting, it is a good idea to go to A&E.