The issue is caused by the difference in config between the physical interfaces. The L2 config o f the interfaces needs to be identical for them to be able to bundle. The way I found around it was to admin shut one interface so there is only one act...

No the article is correct.  We're talking about installing routes into the routing table, you are talking about packet forwarding. This is about a control plane operation not a data plane operation. The prefix length isn't considered when installing ...