I bought a s7 edge off ebay. Everything worked fine until I downloaded the oreo update. Now some apps won't work because they say my phone is rooted. Has oreo caused this or has it been previously rooted? Cheers
Usually if the phone has been restored back to stock all traces of the root are removed @Stig0001
It's worth checking your Knox Counter in your phones settings to see if it's been tripped and download PHONEinfo from Google Play Store to see if that shows up anything.
From a Google Search there are lots of other ways to determine if a phone has been rooted but some include downloading software.
As I have not used these software's I cannot endorse them or pop in links to them.
Using these are at your own risk.
Finally a Samsung Service Centre or Samsung Experience Store would be able to check the phones status too.
The Oreo Update shouldn't affect the phone as you describe.
I'd suggest to first try deleting the phones system cache file by turning it off and then from a set series of button presses will take you into the System File Cache and clear the files.
If that fails to help then back up and Factory Reset.
To add >I'm assuming the apps in question are banking apps etc ? Try going into Settings, apps, find the apps and then go into their storage and clear their cache and data then close it down. Soft reboot the phone by turning it off and on and then try launching the app again.
Current Phone ~ S8 Model: SM-G950F. CsC:BTU.
Samsung Gear s3 Frontier Watch