Okay, I reproduced the problem and to be frank I have no idea how and why it appeared, especially since downloading the pack and installing it on vanilla Native was the last testing step I did before releasing the pack in the first place.
At the same time, my experimental (and much more complex) version of the same code works without a hitch which is even more confusing.
Frankly with the amount of map icon-related problems I very much want to put the blame on the engine (especially since it does have the tendency to ignore icon textures at the smallest opportunity) but some more thorough testing will have to be done before I'll be able to do so.
Anyway, the answer for now is simple: I have no idea what the problem is and no idea when it's going to be fixed. Sorry for that. Until I solve that issue, it is recommended to try the solution outlined in the previous post: put all regular icons first, put a number of reserved placeholder icon entries for later expansion, and then add regular flags at the end of the list. If you need to add regular icons later on, you can replace some of placeholder icons with new ones, and if you need to add extra flags you can simply slap them to the end of file.
At the same time, my experimental (and much more complex) version of the same code works without a hitch which is even more confusing.
Frankly with the amount of map icon-related problems I very much want to put the blame on the engine (especially since it does have the tendency to ignore icon textures at the smallest opportunity) but some more thorough testing will have to be done before I'll be able to do so.
Anyway, the answer for now is simple: I have no idea what the problem is and no idea when it's going to be fixed. Sorry for that. Until I solve that issue, it is recommended to try the solution outlined in the previous post: put all regular icons first, put a number of reserved placeholder icon entries for later expansion, and then add regular flags at the end of the list. If you need to add regular icons later on, you can replace some of placeholder icons with new ones, and if you need to add extra flags you can simply slap them to the end of file.