Intermittent SSL handshake error 525

Currently I am still facing intermittent error daily and until now still cannot be resolved.
I read up some of the forum and understand one of the points which not sure if could be the cause.

In our cloudflare DNS records, we have 6 ‘A’ proxied records, below:
A burno 210.10.158.94 Proxied [Edit]
A burno-uat 210.10.158.90 Proxied Proxied [Edit]
A Pbx 210.10.158.92 DNS DNS only [Edit]
A Sftptest 210.10.158.93 DNS DNS only [Edit]
A staging-aaa 210.10.158.97 Proxied Proxied [Edit]
A xyz.com 210.10.158.95 Proxied Proxied [Edit]
A www 210.10.158.95 Proxied Proxied [Edit]

These uses different subdomain and I suspect Cloudflare may not able to determine the correct domain.

For example, visitor is using burno.xyz.com to the site, and somehow halfway after maybe 4-5 hours of session, it throws this 525 SSL handshake error.
At the same time, visitor is also using burno-uat.xyz.com

Can this be a possibility that the 525 error would show up, or there may be some other reason.
Have checked that SSL cert is dedicated bought from Cloudflare, and valid, and port 443 is allowed.
It will go back to normal after 1 min.

Anyone can advise? Because this is really a headache and affecting our clients.

Thank you.