A thought. I observe and experience frequent communication problems in Taiwan, compared to Japan or the US. They often manifest as someone asking a question and the person answering giving an answer that doesn’t match. Either the person asking hasn’t properly formulated the question, or the person answering hasn’t properly confirmed it.
Could it be because the current generation of people speaking Mandarin was raised by a generation who spoke Taiwanese natively? It’s as if Germany suddenly mandated that English was the official language, and everyone schooled and raised their kids in English, and even prohibited use of German in school, even on the playground. Some people would be able to speak good English; others – not so well. And many people would be frustrated by the act of talking, and try to take shortcuts.
Former president Lee Teng Hui (just two presidents ago) admits his Mandarin was so bad that he spoke with former First Lady Soong Mei Ling in English.
Maybe I need to assume everyone is a non-native speaker, and take conversations more slowly.