The UI is fixed. The correct domain records should show up if you’re not configured on Cloudflare yet, so when you check the box (or if you have already) you now have instructions on what to change your records to.
YOU MAY EXPERIENCE DOWNTIME WHENEVER YOU CHANGE DNS
Cloudflare takes a small amount of time to validate a domain, on the order of minutes
Your DNS provider might not change your records instantly; mine takes up to 12 hours. So errors might not start showing up right away.
If you’re not sure if your records have been broadcast across the internet yet, use the Google online DIG tool to check to see if your CNAME is up-to-date.
You’re looking for the line that says “CNAME app.bubble.io”
id 42732
opcode QUERY
rcode NOERROR
flags QR RD RA
;QUESTION
www.mytestwebsite123.com. IN CNAME
;ANSWER
www.mytestwebsite123.com. 299 IN CNAME app.bubble.io.
;AUTHORITY
;ADDITIONAL
If you’re using an ALIAS record, you’ll see an A record, as follows:
mytestwebsite123.com. 299 IN A 104.19.241.93