WebUI Agent Bakery in loading loop after Update to 2.5.0

CMK version: 2.5.0
OS version: Debian 13

Error message:

After Upgrading a distributed environment to 2.5.0 we cannot access the Agent Bakery via the WebUI (/check_mk/wato.py?mode=agents). The Browser keeps loading with no end.

All in all the sites contain 65 Windows Hosts and 30 Linux Hosts with agents.