@spiggot One of my Solos have a button that doesn't click when pushing in it feels like I might have a bit of herb trapped along the edge. I've tried with a tiny needle to scape along the edge but I didn't want to do too much and break the button. I just left as is. It doesn't cause any problems, mine isn't loose in any way. I've tried shaking it and turning it upside down with no luck.
If your button is loose though it's only going to get worse. You might want to think about warranty soon.
EDIT
The reason I suggested to use the warranty possibly because it's something that you said changed about your unit. I would listen to
@OF. He's our go to guy, he would be who I would listen to.

So never mind as to what I said.