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!!