Ketone urine strips are notoriously inaccurate especially for assessing nutritional ketosis. If they are very dark it shows you are still excreting ketones and they are not yet being used efficiently by your body. Also they can be quite impacted by your level of hydration.
You are probably in nutritional ketosis but your body hasn't adapted fully to running on ketones as opposed to glucose so you are spilling out some.
So long as your blood sugars are under control and you are not taking SGLT2 inhibitors you should be fine. But if you aren't eating a lot I would suggest trying to have a bit more although your hunger will probably re-appear when you become fat adapted and you start running on ketones completely.