How can i tell if my phone has ever been rooted?

Banking apps can be not running when they think the phone is not safe even the phone is “not” rooted . And factory reset or OTA update after rooting can make root access botched. Just like unrooting phone. So root checker apps can’t detect rooting after factory reset. Then can i tell whether my phone has ever been rooted before factory reset without checking knox? (Cuz broken knox doesnt necessarily mean rooting.) My phone is reset . Root checking apps say its not rooted. But banking apps dont work. Is thery any way to check..?