I have an existing Sharepoint 2016 On Prem install that I deployed the App Catalog to, as per several online guides, about 2 years ago. We use K2 so had to install then deploy the K2 App for Sharepoint. Everything has been working fine since the install. I setup a new domain (lets call it myapps.net) as per guidleines and installed a wildcart SSL cert for it (*.myapps.net).
So I have: intranet.mydomain.com as my main SharePoint site and myapps.net as my App Catalogue site/url and DNS setup with appropriate Cname records, wildcards etc so that when I ping randomnameornumber.myapps.net it resolves to my sharepoint sever's internal IP correctly.
I recently upgraded K2 4.7 to the new K2 Five. All went well with that then I deployed the new K2 Sharepoint app - it saw my App Catalogue fine and installed to it with no errors.
And this is where my issues start.
In Central Admin on my Sharepoint Server I go to: Manage App Catalogue, then click on the Site URL: https://myapps.net/sites/apps and I get a 'Page Not Found' Error - myapps.net's server address cannot be found.
IIS is working fine, all sites up and running, bindings are all still in place, I can still ping random.myapps.net and it resolves to my sharepoint server fine. I've re-booted the server, stopped and re-started IIS etc all services are up and running, Sharepoint itself is working fine for all my end users etc
Just can't get into that app catalogue anymore.
I've double checked my AD Servers DNS and all entries are still in there as per the guides, nothing has changed there. Rebooted those servers, cleaned cache etc
And, to make matters even stranger ... I can type in https://myapps.net/sites/apps into any external PC, it will prompt for login, and it shows me my bloody App Catalogue I can't get into internally on the domain! My new K2 Five app is sitting there as it should after being isntalled by the upgrade, but, if I click my K2 Five app that I can see in there, I now get the Server IP cannot be found externally now as well.
But the point is - the App catalogue is there and my new App is there ... I just can't access it internally for some reason.
It shows the app url as: https://apps-e19ecb1c2ea8bf.myapps.net/sites/apps/K2forSharePoint/Pages/Settings.aspx?SPSiteURL=https%3A%2F%2Fmyapps%2Enet%2Fsites%2Fapps which all appears to be correct and pinging apps-e19ecb1c2ea8bf.myapps.net internally resolves fine to my Sharepoint server as it should.
I'm at a loss as to what to do next. Any ideas would be appreciated as this is driving me nuts for the past week!
*Edit - Question appears 'On Hold' due to 3rd Party app - actually its nothing to do with K2, its a Sharepoint specific question in regards to the bindings in IIS to do with the App Catalogue. I only noticed it after I upgraded the K2 app as I had not tried to access the App Catalogue since the initial install.