Svea stove doesn't get hotter than simmer - Optimus Svea

I've had 2 other svea stoves - I bought the first one in the mid 70's, and my second one in the early 90's. The first two ran really strong for 20 plus years. This newest one has been a disappointment, as it's a bit sluggish in lighting, and I can't get it to run stronger than about a low simmer. The first 2 units would run in a strong wind and this one won't even light in a light breeze. Checking youtube, it seems like perhaps the modern ones just aren't any good any more?