For help: Dual-nic dual-Gateway and CIDR Block interconnection issues

For help: For the problem of dual-network card dual gateway and CIDR Block Interconnection-general Linux technology-Linux technology and application information, see the following for details. The current situation is:
A linux server with dual NICs, one with a public IP address, and one with an intranet IP address. The Gateway is set to a public network gateway by default. There are multiple network segments in the LAN, and the server is configured with 192.168.100.201,
Problems:
Because the IP address of the 100 CIDR block is not enough, the IP address of the 6 CIDR block must be used, but the IP address of the ping 100 CIDR Block except 192.168.100.201 can be pinged, the ping6 CIDR blocks of CIDR Block 100 cannot be pinged, and of course the gateway cannot be pinged,
So I would like to ask you where the problem is?
Note: The above layer-3 Switch has no limitations between CIDR blocks, and dual gateways are also implemented in linux.

Thank you.