As well as this issue I also found that when I went to buy lounge access with miles* I was presented with some unrendered code rather than a working page. I called TAP to fix the passport date issue, which they were able to do, but I couldn't process the lounge access purchase because the price for that is higher on the phone than the website, and I didn't have enough miles. The guy told me that the website was known not to work properly on Apple devices (!), which was bad news for me because I only have an iPhone, iPad, and MacBook... In the end, Firefox on my laptop actually worked. But still, absent extraordinary circumstances I can't imagine choosing to fly TAP again if I have options.

*I had 10,000 or so miles in my account from the status match promotion four or five years ago and which were due to expire before the end of the year. I will not add to them or be able to use them for flights, so burning them while I had the chance for something that I will actually use and value (my ticket already included priority boarding and security etc.) made the most sense.