thanks for answering. Here is my returns dealing with the fix list:
"You changed to Cloudflare name servers prior…“ > No
“Add IP addresses to the glue records…” > As I understand, glue records are useful for DNS managed by an other platforms than the one managing my web site hosting. So, this is not my case (website hosting and DNS are managed by the same platforms)
“Move to a different DNS provider prior…” > I don’t really want that…
“There is a typo in the name servers on your registrar…” > I don’t see anything…
" Go to this DNS testing site and select the ‘Trace’…" > No errors
“It’s an intermittent issue where…” > I don’t think so. I’ve tried severals times at different moments.
“You previously had DNSSEC enabled for your zone…” > I don’t see any DS records
" You are trying to add https://example.com…" > No
I’ve contacted my web host to get further information especially concerning an error in the Whois : 500 SSL negotiation failed.