Can not login fron within an iframe on iPhone and iPad

I included the grafana app in my my web-site by using iframe,like this simplified version below:

iframe src ="http://192.168.5.39:3000/dashboard/db/Stromzaehler?orgId=1&from=now%2Fd&to=now%2Fd&panelId=1&width=800&tz=UTC%2B02%3A00" width='100%' height='900'

This works perfect on Win7/Win10 Platform with both Firefox and Chrome. If no cookies are set, i will be redirected to the login panel, set my credentials and voila’ I am in!!!

However on Iphone or Ipad; After entering credentials the login Panel is simply reloaded asking me again for credetials… - forever…

Environment:
Webserver: Apache (on Host-A)
Grafana Vers. 4.6.1 (commit: cac8b97) (on Host-B) - fresh install
both hosts are on my local (private NW)
thanks erwin

Sounds like a cookies problem - when you log in a session cookie is created if it is being blocked or removed then you will get redirected to the login page again.

You could start by googling Mobile Safari and iframes and cookies and see if you find anything.