Problems with Reverse Proxy Setting

Hello,
I had Running grafana in my Home Assistant perfectly and was using it mainly on my iPhone.
Then I was trying out VPN-Clients and did some Updates in Home Assistant, as a result, i couldn‘t Open grafana any more on my iPhone (See attached error Massage). So i can’t really say, what really the reason is. But it works fine on my pc and Android Tablet. From the error Massage it Sounds like some Reverse Proxy Settings are causing the Problem.
Can anybody give me support, How to solve this?
Kind regards, matt

Kind regards

Did you try private browsing / another browser / clearing cookies and cache?

i am using the integration in my home assistant app on my iphone. So it is not within the browser.