Wordpress portal - issues while admin posting new posts - large database queries

Job ID: 33872477

Budget: $30 – $50 USD

Our client has a large VPS but the issues are not on the front page they are in the dashboard.
The client has 5 admins and when the admin is more than 1 it takes a large time to post a new post and sometimes (a couple of times) it shows a 524 error from Cloudflare. That's only happening in the dashboard.
The server is a 12 CPU core, 32 GB ram, and the client is using a max of 20% of the resources from the server. The database is large about 1.5 GB. We need and server/wp expert who can resolve this so that client posting new posts is taking super fast. I think this is an issue but possibly something else: the client's previous work was in the waiting queue for queries to be submitted that's why pending queries make it a timeout error.
We see sometimes in the terminal that cpu/mysql is 1000% (we have a print screen couple days old).
Related categories: PHP WordPress MySQL Server CentOs