Media Encoder Not Opening Automatically from Premiere Pro

I'm trying to export a video from Premiere Pro to Media Encoder, on a MacBook Pro.  (Both programs are up to date as of today.)  I'm used to seeing Media Encoder open automatically upon pressing "Queue".  Now, however, I get an indication that the video is exporting - I don't know where - and Media Encoder doesn't open automatically.  When I open it manually, the video's nowhere to be found.
(I've set up the video to save in "iCloud Drive," but I can't find it there either.)
Please help ... thank you!