2021 Back up file format uses 2020 icon

Upgraded to SU 2021 Classic and have noticed backup files use 2020 icon.
Not really a problem but curious as to why and maybe I have missed changing or setting a setting somewhere

Have you linked your backup files (.skb) to SketchUp 2020? By default backup files are not linked to anything and show a blank icon. This could happen if you right-click on a .skb file in Explorer, select “Open with…” , select SketchUp and leave the “Always use this…” box ticked.

Thanks Anssi
I think you are onto something
My skb files seem to be linked to my earlier Make version
Tried using ‘properties’ to change which program opens file without success so far.
Will keep at it