recording to computer - layout issue + disappearing speaker video

Hi!

We used to Record to Computer our webinars and the layout was set to show the shared screen (i.e. a ppt presentation that occupied 3/4 of the monitor) and the speaker's video (a thumbnail size sitting next to the presentation). 

Something's changed recently on Zoom (an update?) and the speaker's video shows on the top-right hand corner of the monitor, over the shared screen, then it disappears, only to display the shared screen.

We tested the following scenarios:

Host = Sharing screen = Speaker

Host = Sharing screen = Not the speaker

Has anyone got any advice? 

Thanks for your support, 

AM