[Android Central Question]

I got root for my J7 Prime SM-G610M yesterday and since then I haven't been able to unlock my phone quickly. It takes about 5 seconds to unlock the phone and I hate it. Fingerprints seems to be perfect though, but when they're not recognized I don't wanna be waiting 5 seconds everytime. I contacted a live chat samsung service and the guy told me to hard reset, did it, didn't work, then he told me to do a factory data reset, I was trying to avoid it since I had already done that. But I ended up accepting, did it and it was still there. Finally the guy asked me if my phone had been rooted or flashed before, that's when it hit me. It was indeed, He said that the best was if I took my phone to a samsung center for them to re install the software and remove the root. But I'm not expending any money on this phone since I plan on buying a new one or christmas, and I DON'T want the root to be removed, that's why I got it in the first place. so, can anyone give a solution for this? Thank you in advance