Since gaming now lives at http://YouTube.com/gaming , the old Gaming app is going away on May 30th! If you were subscribed to channels in the Gaming app, they’ll automatically move to your YouTube subs feed on May 14th. More need-to-know info→ https://yt.be/help/yRe4
We'd like to help. If you're using a desktop computer, try clearing the browser's cache & cookies to see if that fixes the issue? Here's how: https://yt.be/help/Cko1 . Also, try using a different browser or Incognito mode to check if that makes any difference. Keep us posted.