Trees

Indica vs. Sativa: let's talk about this for a second. There's no difference between them other than how the plant itself look botanicaly. There's a common misconception there, that was mainly contributed to by myth and legend over the years. What matters is terpene and canabinoid make up of the flower of a strain. Don't shy away from trying hybrid or sativa strains.

Cannabis use also may hinder active sleep while high. Due to the psycho active properties, it can lead to the brain not wanting to enduce a REM state of sleep. That being said the come down, or "burn out", may infact help one fall into a sleep easier. This is potentially caused by a post dopamine blast a thc high gives, you're brain likes dopamine and sleep also provides this, thus triggering your brain to want to sleep.

Play around with strains with higher levels of myrcene and humulene terpenes, as they are said to help induce a tired sleep state. Also look into higher CBD% strains. It's common for dispensary weed to be high THC% with lower CBD%.

Maybe try smoking a bit more, a bit earlier before bed so you hit the burn out stage slightly earlier and with a stronger presence.

Also I'm personally not a fan of these distillate carts(unless i make and fill my own), they seem very inconsistent and who knows wth they put in there to increase viscosity. Potentially look into getting somthing like a Dr.dabber and buying concentrates like live resins/ full spectrum extracted concentrates that are not mixed into a cart solution. Might give you a more accurate/consistent result vs carts.

I'm not a doctor nor "professional" in cannabis. But I've smoked for a long time, have grown many a plant, and am a hobbiest concentrate extractor.

I believe it has to do with the strain itself and the THC/CBD/terpene ratio. Some will go to the old indica/sativa argument but I've found some sativas make me sleep and some indicas don't, so it all really boils down to the primary terpenes and the CBD ratio. Caryophyllene, Nerolidol, Myrcene and Linalool are the top terps for "sleep", so if the strain is high in those, that may be what you need 👍

Look into dry herbal vaporizing instead of using concentrates for more consistent results. Different temperatures cook out different active compounds from the flower.

This lets you select your favorite temperatures depending on time of day or mood/strain. For example if you only have indica-leaning hybrids but want the uplifting euphoric affects of sativa, you can vape the hybrid at lower temps to extract the sativa side. You won't get as much vapor but it will only release that side of the herb.

If you desire sleep, I'd be focused on higher temp vaporizing with a CBD or indica dominate strain.

I find it simmilar, I try and let it wear off completely before going to sleep because I wake up groggy if I don't. The biggest factor for me is how much I did that day, physical or mental. If I am exhausted to begin with the comedown makes me wayyy sleeper than otherwise. Good luck I hope you find out what works for your soon, it could also be that weed doesn't affect it as much as you think, if your sleepness nights occur just as often.

Maybe it's not the weed.
Are you using it every night?
If so, it's not the weed deciding if you sleep or not.