Sorry I did not check this issue for few days now. @shumansk I’ve continuously asked you to open ticket but you ignore my request.
I highly doubt that reboot of server have anything to do with this.
Also the reason CyberPanel keep saying that rDNS is not correct because the results are cached. And when you check your rDNS online you get the correct rDNS but CyberPanel get the cached results.
I highly recommended anyone reading this post that make sure you set rDNS before you try to use this feature because then incorrect rDNS will be cached.