For most people the sign out and in again fixes the problem for good, but it does come up more than ideal. I haven’t checked lately, @Bryceosaurus may be able to say whether a better solution is being worked on.
Here’s a picture of the Westminster CO Trimble building, which is where SketchUp will be when we’re able to go back to an office. You will want to open this in a new window, and use the magnifier to see the real resolution. In case it isn’t clear, most of the image is Digital Globe, and part of the upper left is the Nearmap image laid on top.
When importing there are two sliders, one that goes to 18X, and another that goes to 21X. As you need to buy at least 200 tiles, you may as well take the lower slider up to 21X, and then select as little as you can that exceeds 200 tiles. Having the other slider at 18X will improve the terrain detail.