I'm really struggling keeping my grill hot

For starters, I'm a beginner. I just got a small charcoal grill and a Weber chimney. I am not having any issue getting the charcoals hot. They ash over and get FLAMING red hot in the chimney. When I pour them in my grill, they stay red.

I cover the lid, open bottom and top vent. Wait a good 10 minutes or so to let it heat up, then put the burgers on (i onl_ have tried with burgers).

But after they have been on for over 10 minutes, I check them and the coals are not lit at all, just all gray, the 1 side of the burger is not even cooked, and the grill just feels warm.

My grill is clean, no ash buildup...I am lost. This is my second time using it, but it just seems to not stay hot. I can literally place my hand on the lid and keep it there after it's been about 30 minutes.

Any advice is really welcome!