It seems that there is a bug or a limitation.
When embedding a Youtube video on a canvas, it is very hard to resize the window.
(Btw a Bug report section in the community could be good).
It works very well on Firefox, but not on Chrome.
Dear @tomavatars,
I have had the same experience, but when I switched off to block “trackers and cookies”, the edit mode in the right top corner became available. Seems to be that “big brother” Google enforces monitoring 
Screenshot from my “Brave” browser
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