We had to move our website to another server and reissue the certificate. The host is Windows 2022 running [Asp.Net](https://Asp.Net) on IIS10. The certificate is issued by Lets Encrypt and shows valid.
[Certificate Print Screen](https://drive.google.com/file/d/1axTuKBp4S0ubGsAKmo2coGFkZsscBqkx/view?usp=drivesdk)
Devices, other than the iphone, can access the website without issue. If the Iphone has visited our site previously, it gives an invalid certificate. If the Iphone has NOT visited the site before, it doesn’t give any errors. This only occurs on clients who were accessing our website on the previous host.
[Safari Certificate Error Message](https://i.postimg.cc/J0MSxCHj/safarierror.jpg)
What I’ve tried on the Iphone:
1. Clear history and everything in Safari. Restarted phone.
2. Reset network. Restarted phone.
3. Tried using Chrome on the same phone, still got the invalid certificate message.
Only one person in our office has an iphone and luckily, they visited the site before the move so they are getting the error. We were able to test the above and have had no luck in accessing the website.
Anyone have ANY suggestions on how to resolve this? I’m not that familiar with iphones so I’m not sure what to do at this point.
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