It looks like the static LAG was configured for uplink sharing port on Summit 200 but the LACP is configured in x440G2 switch now. The LACP should be configured/enabled on peer switch as well to operate properly. So if there is no LACP configured on the sharing port in LWL Core, you need to remove the "LACP" from your sharing configuration.
And all access ports were configured as untagged ports of the "MyVLAN" VLAN but only port 1 is untagged for the VLAN in x440G2 switch. You also need to add customer device ports to the VLAN with untagged.