They who write in Latin or Hawaiian only may encounter less problems with their surplus on alphabetic signs, than other who miss one.
To get back to @central on the statement, that it might be an OS related problem: I hope so for the Mac users. There is a problem however, one that every Dutch speaker will encounter sooner or later, once or more often, they might not solve that way either, simply because the combination does not exist in Unicode, not as a ĳ-ligature, not as a combined íj-character-set.
Dutch writers often use accents like in 'Zĳ doet het wéér' 'Híj doet het weer' or 'Het dóét het weer' to write the exact location of the stress in the sentence, thus avoiding misinterpretation. As you see in the example, the second vowel of the digraph is accented too. There is no such thing for an ĳ (on capitals it is rarely or not used), nor does the 'j-accent aigu' (a consonant after all and alas not used in any central-european character set) appear in Unicode. And still, both í and j should be accented; the example shows íj unclear as íí would have been, thus screwing up the digraph.
For @Axidiel this problem may serve as example, that Ĳ still IS considered one letter / dighraph, even when typed and sorted I+J.
Of course, when handy enough, one could adapt the ligature and/or single j to bear the accent in the most used TrueType or OpenType typefaces (works for printing only, not online for obvious reasons) and save it in the Unicode free spots. If keybinding truly works on OSX and thus iOS keyboards, if iOS supports OpenType fonts, that might be a problem solved. In Android one might get it working per project, but I truly hope for keybinding of a unicode free room symbol on my Textblade instead of a deep search in special symbols each and every use.
FYI: the accented version was not available on Dutch mechanical typewriters either. There was an Ĳ-ligature right of the L, but stress was to be added by pen later on. Lead-type presses used it though.