hi
there is a missing command when you set OSPF and it gives the ability to configure maximum-path (ECMP) , example on FRR:
### FRR router ospf auto-cost reference-bandwidth 100 timers throttle spf 200 1000 10000 maximum-paths 64 network 0.0.0.0/0 area
VyOS-CLI command set protocols ospf maximum-paths '4'