I never experienced that problem with the Baby Bjorn so I don't know what to tell you. Have you checked to make sure you have the correct settings? It should tell you where to set it depending on your LO's height, start with getting that correct, and then make adjustments from that if it's still off. I never had a problem with the Baby Bjorn, and enjoyed using it until DD got too heavy for me to wear her that way. Then I transitioned to the Ergo Baby Carrier which I am still using now, and we both love it ... it didn't work out as well when DD was smaller, but it's perfect now that she's bigger, much easier to get her in and out of.
Is your LO facing inwards (towards you) or outwards?
I have a Maya Wrap which I tried a few times. It just never worked out for us. DD didn't really like it that much, and she'd overheat in it.
Yeah, she's got DH's overheating gene. So that was gathering dust for about a year before I finally washed it and stored it away.
Do you have a store in your area where you can try out various carrier options? For example, there is a store near me called Lullaby Lane, they sell all sorts of baby stuff, and there is a section where they have tons of sample carriers for you to try on to get a feel for it. Maybe you can find such a store in your area so you can sort of try before you buy another carrier.