What is this symbol

[Sunshine_8720]

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[Milind06]

auto rotation

[Faraz_F34_5G]

When you open an app, screen will rotate as you rotate phone (except upside down)
charging in landscape and vertical

[Sidhabhi]

If you are talking about status bar..that is data saver icon..

go to settings>connections>data usage>turn off data saver option

[Dileepsalian]

data saver