Although I have previously mentioned that quite a few non-native speakers tend to incorrectly pronounce letters of the English alphabet (see here), including the X in x-ray, I believe that my recent observation warrants a separate post. Specifically, I noticed that it is common for German (and likely other) native speakers to pronounce the X in the English abbreviation for user experience, UX, in German but the U in English. Even worse, they would pronounce three of the four letters in the common term UI/UX (UI: user interaction) in English but the X in German.
Because it is widely used, UX even has its own entry in the Oxford Learners’ Dictionary, complete with phonetic spelling and audio examples, see and listen here. The correct pronunciation has the phonetic spelling [ˌjuː ˈeks], whereas the common incorrect pronunciation would be [ˌjuː ˈɪks]. I also checked a number of English videos on the topic of UX on youtube, all of which used the standard English pronunciation. This seems to rule out the possibility that it is common to pronounce UX different than expected, perhaps comparable to the example of SQL which is often pronounced like the word sequel by experts, see here. In contrast, the very first German video on UX I came across has both speakers pronounce the term consistently but incorrectly (that is, as [ˌjuː ˈɪks]) even though they seem to be very familiar with the topic or even working in the field:
A possible explanation (but not an excuse) is the fact that the X in UX stands for experience and the latter is usually pronounced as [ɪkˈspɪəriəns], listen here. However, the pronunciation of an acronym is in general independent of the pronunciation of the words the letters stand for.