Short answer: Ensure you have your Bing Rewards account handy, both Bing and Live/Outlook email etc. Now on the browser clear all caches, emptied all history and so on, basically cleared everything. Then close your browser, log back into Bing Rewards again and start searching, you should see earnings. If it still doesn’t work, you might be flagged for violating term of services and soon your account may get cancelled, but please email Bing Reward support, don’t take my word for it.
So the reason I blog this is because I encountered the same problem. I used Bing search engine frequently and I noticed one day I no longer earned any points or credits, was worried. Then I tried to do research online to see if anyone encountered same problem, and indeed there were many, but the majority of the people are cheaters, they searched with bots like pogo-bots and bingpong bots.
For me, I used real search Bing.com, and still encountered same problem, and the fix was to logout and log back into Bing rewards, if that don’t work then clear all history and caches from your browsers then log back into Bing again.