Amazing, that did the trick. Thanking youTry:
1)
• Give the Cell a Range Name eg DayOfWeek.
• Load it to Power Query > Data from Range
• In PQ for that Query removed the Promote Header & Changed Type steps
• Load as connection only
2) In the orginal Query
• Add Custom Column
• Enter "= DayOfWeek" (without the quotes)
• Expand the column and give it a column heading