Most of what we found so called "top exchange" are not true sometimes. Based on my experience, some of them are den of bots and crappy things that spam the exchange to fake the volumes. So you have it experience them yourself. P2PB2B is an example for that. What funny is they claim themselves as one of the best exchange out there. Try Binance or Houbi, good exchange and been operating for a long time. Also list only good altcoins in the market.
Fake volume on the exchange now it is a public secret. Thanks to Bitwise for doing research and finding this fake volume problem with data.
And only 10 exchanges are recognized by Biwise as exchanges that have real volume, one of which is Binance. For Huobi it seems they are fixing their volume, because
since 2019 the huobi has stopped misreporting the volume.