First, you haven’t actually got a plan view of the model. The Camera is angled slightly in SketchUp. You can tell that because the word “TOP” is not displayed in the upper left corner of the SketchUp model window and the fact that the vertical blue axis is visible.
In LO you can tell that because the SketchUp Model panel shows (None) for the Standard View.
If you select the 4527 dimension you’ll see that it shows the dimension has no scale. This is due to the incorrect set up in SketchUp.
The fix: First select the Standard Top view, Zoom so the model fits the window. You need to be creating scenes in SketchUp to use in LayOut. Using Last saved SketchUp view is bad practice. Save the changes.
Update the model reference in LayOut. Delete one of the viewports. You have two stacked on top of each other. Choose the Plan scene and set the scale to 1:50. With the setup done correctly in in SketchUp you’ll be able to set a scale correctly.
Replace the the dimensions. Make sure Auto Scale is turned on for the dimensions. It normally is and should be in your model but I’ve seen users turn it off without understanding what they are doing.