Yes, I do sometimes wonder if people have actually tried other airlines' sites. In your list AA generally does work for me, but Lufthansa, KLM, Air France, Qatar, Cathay, Aer Lingus, Iberia, LATAM are all on my hit list for this. In the case of Iberia, a high percentage of their the contact centre staff seem very poorly trained too. The LCCs tend to be more robust in terms of both Apps and website functionality, but these are airlines that don't do anything remotely like Upgrade Using Avios on a 2-4-1 voucher with 3 sectors out, 4 sectors back.