I really want to thank devnull for helping me solve some issues to get my Install accessible from the internet.
I am extremely grateful.
I now have Nextcloud accessable from the internet but it is not yet secure.
After talking with devnull they suggested I start a new thread with the below details to help diagnosis this.
a.) i use docker for nextcloud
b.) i use linuxserver.io certificate
c.) there is acually no CA for the certifcate (look in browser info)
d.) post link https://docs.linuxserver.io/images/docker-letsencrypt
If there is any info I can supply to help, please shout.