something is very wrong with site

I rebuilt a site for a client, we use uptime robot and for a few week keep getting down/up for about a minute. Talked to host and they did "some things" and looked at other sites since it's a shared hosting - but still persists - tho not as frequently. I also had to disable all wpmu plugins - because they couldn't get into edit posts/pages. Now it is still happening. I have done a clean install of wp - Divi seems to have trouble loading and often when going to edit a page, I need to refresh to get the page. Now I just went in, disabled some more plugins - got to add a new post - but the side - slides are missing so I had to arrow up and down the page - help!!