I just went to go into Lazada on my laptop but the website came up in Thai and then changed to English and the top section where you "Login" was different, it did not have the "Login" button but a "Sign In" button instead which did not work. I checked the "Language" button and it showed that I was in the Thai language so I changed the language to English and the whole home page changed to the way it should have been with the "Login" button. So maybe this is the problem when people are saying "when they try to "Sign In", there language setting has changed in the Lazada website somehow and they have a "Sign In" button instead of the "Login" button. Check your "Language" setting when you have a "Sign In" button