If I may edit your description a bit for the sake of clarity.
What you’re doing is bound to cause unexpected results.
This is the correct way to save a component to your collection:
• Created the component and give it a name.
• Right context click on the component > Context Menu > Save As … the Save As dialog appears.
• Navigate to the desired directory > Save
Here’s what happens using Context Menu > Save As
When you save a component to a directory via Context Menu >Save As it creates a .skp model file.
However, SketchUp does a little magic trick in the process.
There’s a difference between a component .skp file created via Context Menu > Save As and a .skp model file created via File > Save
The difference is…
The .skp file created by Context Menu > Save As does not contain the component definition.
That’s because when it’s brought back into a model via the Components Browser the entire .skp file becomes a component definition (file name and all) and if there were a like named component in the file it would end up a redundant copy nested inside.
• Remove the model file you placed in the collection folder and place it elsewhere, say, the desktop.
• Open the file and confirm the component doesn’t have another component nested inside.
• Then save the component to the collect via Context Menu > Save As