Hi @LarissaWeber, here's another workaround: resize the Flow panel. 😂
This morning I started exploring the "Flow button for Excel" feature for the first time.
I immediately stumbled into the missing RUN icon issue. ☹️

I tried your "Edit the flow" hack and it worked.
Anyway, since I would like to introduce this feature to a customer I thought I couldn't ask him to edit the flow each time he wants to use the flow automation. Then I started play around and found a very stupid still effective workaround.
If you enlarge the flow panel enough (>=770px) the RUN button appears again.

This workoaround works on my external monitor (24") but not on my laptop (15").
What can I do to have it working on the laptop display?
- enlarge the panel as much as possible
- reduce the zoom (CTRL + scroll down) on the web page displayed inside the panel
I know this is far from ideal but at least it's an easy workaround.
I'll create a request to Microsoft to fix this.
Hope it helps.
Luca