The pronounciation of 'ein' is 'eeen' here, and, on forvo, both ' eye-n' and 'ey-en'. Sorry - have forgotten all the phonetic symbols gor these sounds so this is not very helpful! But there are 3 distinct and different pronunciations just in these two apps. Are all 3 used? Maybe even more are? Some more than others?
Any advice on which to aim for?