Since I don't see any similar kind of answer here with same experience with issue or any solution, you can directly check with support team here and they can say if something was changed from RC side and help you to resolve the issue

I spent some time with Support and they saw no problems on the RingCentral end. The system changed all of my settings and the Audit Trail shows me making the changes. But I didn't. And the many changes all happened in one minute according to the log; no way I could have made all those changes that fast. Also I know two other RC users who had all of their forwarding rules changed around the same timeframe. They did not make the changes. After spending time with Support, all they recommended was to change my password and security question. No other explanation given. The issue is resolved, I fixed my settings myself. But there is no explanation for how the changes happened in the first place. I have no confidence that this won't happen again so I worry about customers reaching me properly. It's sad, annoying and may drive me to leave RingCentral. My business is just one of a network of about 75 companies which mostly use RC. Maybe we'll all leave.