So, I guess there are 264 entries in the cache. Issuing “ip dns cache print terse count-only” should return 264 too, instead it returns “561”. Tried multiple times, “count-only” counts are always approx. twice as high as the real count.
For some reason count-only on the “/ip dns cache” level prints the count from “/ip dns cache all”. If that’s not just a cosmetic error for you (i.e., you need the exact count of A records) you can either ask support@mikrotik.com to fix it or run "/ip dns cache all print count-only where type=“A”. That should give you the number “/ip dns cache” counts up to.