iPhone 13 Pro Max chargings issues

My iphone 13 Pro Max won't charge consistently. Apple Store said it is not hardware, so try iOS update and if that doesn't fix it, then reinstall iOS to remove bugs. They also said don't replace all data from cloud and to reinstall apps manually. Won't the corrupted data find its way back on to the phone if it is already saved to the cloud? Also, is this the best way to fix this problem, as it will certainly take several hours to accomplish this task? Thank you in advance for advising.