Please help, near end of flower issues

Yep, pretty common case of overfeeding. Dark green leaves and burnt tips are a good indication that you're feeding too much. I recommend feeding every other watering instead of every watering. Make sure your PH is in the correct range as PH issues can mimic some nutrient toxicity issues. Measure your runoff PH as well. Otherwise you're looking good friend. Enjoy the rest of your grow 👍

This is nutrition burn from nit having enough run off when your adding nutrition. Soon as I seen 1 liter and feed amounts. When you add bottle nutrition you need 20 to 30 percent run off to draw out the salts of old nutrition as it grows. You have a accumulation of salts is the issue. Which is causing a lot of troubles in the substrate. The other give away is where you see nute burn, and deficiency at same time. Plus toxicity of nitrogen in lower leaves. Flowering npk ratio is 1-2-3. Too much nitrogen hinders bud development as well in flowering.

They look way overfed