Looks like a case of the geometry being too small. It’s not really transparent but rather a case of faces missing altogether. Try scaling up by a factor of 100 or 1000 before running Follow Me.
My preferred method for handling small geometry goes like this.
Draw the thing at its normal size. I just guessed on the dimensions for the example and made it 1-1/2 in. long.
Before running Follow Me or doing something else that creates the tiny geometry SketchUp doesn’t do, make a component.
Copy the component and, without opening the copy for editing, scale it up. I managed this one scaling up by just a factor of 10.
Edit the large copy and run Follow Me or whatever.
After you’ve finished editing the the large copy, close it to exit edit mode and then just delete the large copy. The original will get the same treatment and be exactly where you left it.
Not necessarily wrong, but there is a quicker, easier way to model the form.
Generally there’s more than one way to model an object with SU.
Which method is best often depends upon the modeling situation of the moment.
Experiment … Try different approaches to learn how the tools work.
For example; Follow Me will create the entire button form of the in one go rather than piecemeal.