@Mojoryzyn Unfortunately you cannot roll back firmware once it's been downloaded and installed via your phones settings or a factory reset. The reason I think your having trouble viewing text is because your using a theme that's not yet compatible with Samsung One Ui yet. Either choose another theme and let the other theme developer know or choose the stock Samsung Theme for now. I can't advise here how to roll back firmware. Please use Google Search and or look on the xdadevelopers site to learn how. A person doing this does so at their own sole responsibility knowing that a phone can be put Into an unusable state and possible manufacturing warranty being voided.
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