Always use HTTPS problem

Dear all,

we have couple of sites on Azure, which are working well. For one specific site, its a app service, with custom domain i got totally stuck. I use full strict encryption, certificates are ok. Redirect Rules are working well(hostname and uri redirects to https with $1), but as soon as i turn “always use HTTPS” or Page Rules on, i can see that connections on my azure backend are building up. As they reach 2000+ connections, i get SNAT connection limit and app is unresponsive. I have web sockets turned on on CF and azure app. Https only is disabled on Azure side. I have cleaned the cache, tried to get logs with logflare, but still, no luck… any suggestions?

Thank you! Luka