MacBook Pro M1 - Weird problem with projector showing previous slide.

Hi. Have been using my MacbookProM1 running a Powerpoint via Keynote with iPhone Keynote Remote with a newish Epson projector for a year or so - without any problems. At my last presentation (14th Dec) the projector was mostly not displaying the current slide showing on my iPhone and Keynote on my Macbook - it instead seems to be a slide behind - sometimes it eventually showed the correct slide but sometimes it just showed the previous. I tested it again at home afterwards and the problem still occurred.

Anyone else had this? Did you correct? How? Is it Keynote? Apple HDMI? Epson?

When I run the PPT slidedeck via Powerpoint the problem does not occur!

Thanks

Terry