I think (keyword) the problem will be because the hummingbird uses 83/200 sonar with its side imaging, as a combination. The new touch lowrance graphs also used 2d & sonar at the same time. Here's where the problem comes in, you could select 200 on the lowrance and 83 on the bird and have no issue; but the bird won't let you do that! It uses 83/200 all the time, so you can't avoid the interference at all.
This is why I said contact Wayne, he's a bird guru and could be the one to confirm it.