Reset your wifi network settings and after it your problem will be solved.

Facing the same problem 2 days back. As i came to know most of the time this problem happens because of hardware problems like your battery issue or because of water damage. In my case i was facing the similar problem in my samsung s21 smartphone and i was in a bad mood. I searched a lot and found a solution https://okadtech.com/samsung-s21-black-screen-but-vibrates-problem-solution/ In my case i was lucky it was a software crash and i successfully solved this problem.

Initially i was also facing the problem it was so irritating but currently i have just solved my problem. https://okadtech.com/oppo-f11-pro-front-camera-problem-rear-camera-problem-solution-for-both/ Hope this will help you also.