Dear, I 've found an issue with DSA and kernel 5.4.
I'm on 21.02 SNAPSHOT.
My upload speed on WAN is only 10 mbps when a device with LAN connection is linked to 10mbps.
When a device 100mbps is connected to switch all speed is 100mbps not 1 gbps
It seems that the upload speed follow the lowest lan speed...
First test is with 10mbps connection on LAN3. --> Test was done from LAN1 to router.
Second test is with a LAN2 device conneted with 100mbps. --> Test was done from LAN1 to router