Water has been seeping from the toilet tank so it refills every five minutes or so. I had someone replace all the inner parts, including the rubber flapper, but it still does just like it did before. There is no visible leaking and nothing is wet around the toilet.

Did you use the correct flapper? There are differences with some brands. Did you inspect the flapper seat? Is the lift chain too tight or loose?

Sometimes the bottom part of the "flapper" is worn and also has to be replaced, and is not part of most of the rebuild kits. Also is the new flapper sitting down completely against the bottom seal. Those with chains at times get caught or set too tight

50% of brand new floppers you buy are warp and don't seal. Make sure you have good flopper. Also, you may have to replace Fill Tube assembly which makes the seal with flopper. Thirdly, look inside the tank. If water overflows into the overflow tube, than replace Fill Valve.

Hope that helps

Milo