I noticed this last night and it is so annoying. I can't imagine any UX or CX professionals were involved in this new app. So much basic functionality is just gone. 

Just tap this icon in various places it appears:

Just tap this icon in various places it appears:

 

Thank you!  I was controlling the volume on one speaker so it didn’t occur to me to bring up the volume control for my entire system.

Thank you for the responses. I downgraded the app. I got v16.1 from apkmirror.com, this new one is so bad. 

Just tap this icon in various places it appears:

 

I don't see that icon anywhere 

This solution is a good workaround but why remove the numerals from the interface used while listening to music/podcast/etc. ?! The click here adjust volume then apply changes workaround is not the answer.