I use both 2 & 3 ohm standard length Boge carts in 3 ml tanks. Today I put in a new 3 ohm (just checked it - reads right on) in the one tank I'm currently using. Running DIY 50/50 vg/pg menthol plus sweetener - a really clean 'burning' juice, but also noticeably thicker than the typical 30/70 mixes. Normally running at 5 V, so 8 1/3 watts. I just turned it up to 6 V, 12 watts, and the vape was noticeably warm with impressive clouds of vapor and a lot of flavor. I chain vaped it six times and the drip tip was getting warm. I then hit it twice for about 5 seconds each time and looked through the holes in a dark room and did not see a glow. After that I had to let it cool down a bit
I punch my own holes. I've found that I get better performance from these carts if I tailor hole sizes to the juice and/or the cart, starting just a bit small and making them bigger if needed.
So, FWIW, here's my take on your issue Aikhme. It think from what you wrote you are not getting burnt hits right away, which means to me that you are filling correctly. If this is true and you are getting burnt hits after a number of drags, the coil is becoming dry as you vape. Assuming good carts, I would make the holes bigger or thin the juice to solve this. I adjust holes size immediately after the first burnt hit, so I don't ruin the cart.
The fact that you see a glow through the cart holes makes me think there is something wrong with the carts. I've pulled out the filler material a few times after finishing with a cart and I don't think you should be able to see the coil glowing - I didn't in mine either. There is just too much filler in there. I really suspect you may have a batch of bad carts.