SSL Certificate issue with my dyndns.org domain

Yes correct only the port number is differ

Well then we have to confirm that 443 can reach your internal system…
Do you have access to any system outside your home network?
[to use that system to check from]

I’m using data in my phone , if this is ok ?

Phones don’t normally have a lot of tools…
Like: ping, telnet, openssl, etc.
But if you can use it as a hotspot…
You might be able to use another WiFi enabled system to exit through your phone to the Internet.

Ok I will connect my laptop with my phone data , tell me what you want to do

Ideally:
[download openssl if you don’t have it]
openssl s_client -connect YOUR.INTERNET.IP:443

or if that’s not available
[install telnet client - windows add/remove programs and features]
telnet YOUR.INTERNET.IP 443

You mean external IP?

Yes INTERNET is usually external.

Hahahah I can imagine your face.

So replay CONNECTED (00000005)

Yes it was a classic “face”.
Please be a bit more forthcoming.
What did you type/run to get that?
[it looks like openssl - but a lot is missing]

openssl s_client -connect MYEXTERNALIP:443

Only one line of text was produced?

Compare your output to:
openssl s_client -connect google.com:443

Yeap only this but not return prompt. I have to stop it with control C

Yes, big difference with google output

Try these two commands (sequentially and hit enter after each):
telnet MYEXTERNALIP 443
get /

We need to get your server to do it like that.

Then compare that with:
telnet MYEXTERNALIP 80
get /

Is Connected after the first command but no return something after get /.
Both cases , 443 & 80

Are the outputs very similar?
hit enter more than once if needed after
get /

Exactly the same
Connected to myexternalip
Escapee character is ‘^]’
get /

Nothing return