Excalidraw help - Visual note

Hello. I am a millenial in her 40s - limited knowledge of computing and coding. Please be kind. I have only just started to use and incorporate excalidraw into my notes. I love the idea of combining visual and text notes. As i opened my computer and updated the plugin today… Realising, all the visual notes (embedded in markdown mode) are looking like this. Why??? When I toggle back to excalidraw mode - looks fine. Pretty sure iv not done anything to the setting. How do I fix it, please?

What I’m trying to do

This is what it looks like

This is what I would like it to look like….

Things I have tried

Nothing. Too scared… to fiddle with the settings - as for most of them, not sure what the consequences would be!

Help!!!