Why does my axis title keep returning to horizontal (instead of staying vertical)?

everytime I reopen my spreadsheet (after saving it with 4 graphs with a vertical (90) degree axis title, and varying font sizes for axis variables, and then when I reopen all the above goes back to default font size and the worst part is that the asix title (of the y-axis_ goes to horizontal,? this weird, because it hasn’t happened before, please help

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