I purchased a domain. but it loading strange page

Purchased domain www.arun.live and tried to host using the facility of GitHub. Then got the error CNAME arun.live is already taken. . Then I just tried www.arun.live from browser. It loading below page which is totally strange for me. I added picture of page , why because , may be in future this issue will be solved and it may show my actual page, that time readers may confuse. At present www.arun.live loads this page.

I contacted domain provider's help-desk, but they suggests to cross check with GitHub team. and do usual things like flush DNS etc..

Friends you have any similar experience ?

EDIT Updated A Record and CNAME from my domain control panel

root@debian:arun# dig WWW.ARUN.LIVE +nostats +nocomments +nocmd

; <<>> DiG 9.11.5-P4-5.1+deb10u1-Debian <<>> WWW.ARUN.LIVE +nostats +nocomments +nocmd
;; global options: +cmd
;WWW.ARUN.LIVE.                 IN      A
WWW.ARUN.LIVE.          12984   IN      CNAME   https://go-arun.github.io.
https://go-arun.github.io. 2184 IN      A       185.199.109.153
https://go-arun.github.io. 2184 IN      A       185.199.111.153
https://go-arun.github.io. 2184 IN      A       185.199.108.153
https://go-arun.github.io. 2184 IN      A       185.199.110.153
root@debian:arun#

May be some other GitHub user was linked to this site before( Assume that, it was belong to him that time ). and that record still exists in GitHUb. Hence the reason GitHub is giving below error ?

My Conclusions:

• it was a GitHub Issue. Someone another GitHub user was using arun.live as his domain, eventually he lost this domain (may be not renewed on time.)

• I purchased this domain and while trying to add the same domain name, GitHub treating it as a duplicate entry( In GitHub's record it is already taken).

Reason for Above Conclusion:

• If I remove the A-Records pointing to GitHub,that strange page(refer question) is not loading
• I tried to host it from another web-hosting provider and it (arun.live) worked without any issues.