My unit just will not work with the trails and Navionics at the same time. The processor is just too slow. I like the trails, but the Navionics is a great tool so I turn the trails off. The software update helped some. Just learn to live with it.
You can fix that by having less map data.
Get the Navionics+ or Navionics Update card and only load the waters you fish. The less data the unit has to process, the faster it will function.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1