When apps like Ubuntu Software and Files are maximised they do not have title bar buttons. I did see Nautilus window buttons disappear when maximized but they didn't find a way to solve it. It just fixed itself.
I've tried disabling all of my extensions and restarting.
Here are my extensions:
- Advanced Volume Mixer by Hatell
- Applications Overview Tooltip by RaphaelR
- Clock Override by .ext
- Dash to Panel by jderose9
- Lock Keys by kazimieras.vaina
- Media Player Indicator by JasonLG1979
- NoAnnoyance by sindex
- Refresh Wifi Connections by kgshank
- Removable Drive Menu by fmuellner