I have been accessing Blue Iris for the past two years through an OpenVPN server on my TP-Link Omada R605 router, I use the OpenVPN for iPhone app along with the Blue Iris Mobile App. About two weeks ago, I suddenly lost remote access to Blue Iris. I had not updated anything at the time that I lost access and do not have any auto updates set up. I have updated Blue Iris a few times since. I can access Blue Iris on all my devices through the LAN. I have deleted and reinstalled the OpenVPN server several times and have checked settings on my mobiles apps, router, and Blue Iris machine and don't see anything unusual. When I activate OpenVPN on my iPhone, it is showing that I have a connection. I port forwarded briefly on my router to Blue Iris and was able to obtain remote access without using the VPN, but removed it shortly after. I used ZeroTier briefly and found that there was more lag activating it than what I was used to with OpenVPN. Are there some places I should be looking that would have caused the loss of remote access to Blue Iris while using OpenVPN?

Since both ZeroTier and opening a port worked with BI5 remotely to your mobile phone, it appears that BI5, your router and the IOS BI5 app are working normally. It does appear to be OpenVPN having a problem so could your mobile data provider have blocked a specific port that it uses ? Is there anything else on the mobile phone that you can test OpenVPN with ? How about UI3 ? Otherwise it's basic settings check time or try a different port. Do you have another mobile phone you could test it with ?

I did use OpenVPN with BI5 but found it difficult to configure and slow to initialise. My wife just wouldn't use it. ZeroTier on my phone has been excellent and is as simple as opening the BI5 app. I just had a look with my mobile phone on mobile data and at my BI5 server screen and they are very closely synchronised; less than a small part of a second difference.

Let us know if you figure it out.

It is also not working through UI3 and OpenVPN connected. I have also tried to access with my wife's iPhone, but wasn't able to. I'm starting to think that it might be an issue with my TP-Link router and OpenVPN. I saw on a TP-Link forum that a few months ago, there were some posters having trouble with remote access through
OpenVPN on this same router. It was on the prior firmware than what I'm on now, but may be carrying over to the update. I'm looking more into this possibility now. Will probably be going back to ZeroTier in the meantime.

***Update*** Issue resolved. Found out on the TP-Link forum that I needed to open the OpenVPN certificate in Notepad and change or delete a single word in the text before forwarding to my phone for installation.

Well done, thanks for updating here.