I am using Spotify on macOS.
I recently (ie just now) updated Spotify (to ver. 18.104.22.1683.g34a58dea ) and as a result when in fullscreen, the traffic light for controlling the window has disappeared from the top left:
It did not used to be this way in prior versions and since I have not updated the app in a while I can't say which version inbetween where it may have changed.
Now, you must hover your pointer at the top of the display to bring down the macOS toolbar and an unsightly grey bar:
This has also the added effect of covering part of the Spotify window.
Other applications such as Discord, and, older versions of Chrome (prior to ver. **bleep**, so 68 and earlier) always show the traffic light similar to how Spotify used to, in example Discord:
Please bring back the old functionality.