After the Catalina update, the Touch Bar shows a void button on the left of the play button at all times as you can see from this screenshot.
As far as I know, the number of buttons that should appear on the minified control strip is 4... why do I have 5?
If I go into the Settings > Extensions > Touch Bar to customise the control strip, there, while I do the customisation the blank button disappears (see second screenshot).
Why does this happen?
[Edit] As I was looking at this post, with a Youtube tab opened along this, the void was replaced by this icon, that is usually what appears when you have media playing.... I don't know if this is correlated or not. (See screenshot below)