Server in DMZ can no longer be reached from internal networks

Good evening,

I have had the problem for about 32 hours that I can no longer reach my cloud server (domain server in the DMZ from my internal networks (green & blue). From the outside (cellular network) everything works fine.
I haven’t changed anything in my firewall rules.

According to the protocol in the appendix, however, the requests are forwarded

I also use Pihole.
But as already written, the domain can be pinged from the internal networks or the ports that refer to it are open according to the scan.

Edit 10/29/20: Progress after reinstalling the cloud server, I can now access it again via the web interface from the internal networks.

However, access to my files via Webdav does not work, but only from the internal networks.

From outside via 4G everything works fine.