Websites not loading, host ssl certificate error

Hi, I added a reserve ip from my droplet to the plesk server and Cloudflare websites dns but now I am getting host error on my site. I am getting error ssl not valid error 526. How to fix this?

Sites: dthforums(.)com

Click on the error no 526 for the solution if its recurring

Not able to reproduce the error

I tried to check my dns records and deleted the new IP address containing A record from Cloudflare dns and the site is online again now.