Problem with two WAN Ports, since 24.7.6

[SarpeTronic]

The Router is connected to a TELEKOM 250/40 DSL with fixed IPv4 and IPv6 and a O² 5G with dynamic IPv4, reachable over the Internet.
I configured 3 Gateways, one IPv6 and two IPv4 and created two Gateway Group, one with the single IPv6 and one with the two IPv4, all three set to Tier 1, to get the best load balancing, both lines are nearly the same bandwide, with a better quality of the DSL Line, what is monitored under System: Gateways: Configuration.
This worked fine till 24.7.6, the Gateway went first IPv6, than IPv4 DSL but also used reliable the 5G for adding bandwide, now my OPNsense uses nearly only the 5G line, even if it's lower quality and IPv6 is prefered by standard of the OS.