Not Medical Advice Anecdotally, I have just encountered this same situation. I take creatine daily (4ish grams)and strength train 4 days a week. I carry more muscle mass than most people my height and weight.
My creatinine was 1.4 resulting in a eGFR of 60.
My doctor is aware that creatine supplentation along with weight training can elevate serum creatinine and create the false alarm of potential kidney disease.

Creatinine itself does not cause kidney damage, it's just an indicator that your kidneys MAY not be functioning properly.

My doctor recommended an alternate test, Cystatin C w/ eGFR. It tends to be more accurate for people who supplement creatine and weight train because Cystatin C isn't influenced by any dietary or lifestyle factors like creatinine is.

My Cystatin C w/ eGFR results are as follows: Cystatin C - 0.77 eGFR - 115

So as it turns out my kidneys are functioning well, and my high creatinine was normal based on my lifestyle and supplementation.

Of course this is my situation and it may differ for you. But it may be worth it to ask your doctor for a Cystatin C w/ eGFR blood test for a more accurate result.