Stijn:
There is nothing we can to specifically help with this problem. In theory with 365 Business and 2016 Project you should be able to install them on the same machine. Thanks to MS's machinations it no longer always works.
You will have to fight the MS Support "dragon" again. Call support and explain your problem, referring to the link you cited. Although it does not apply to your specific situation it may help. A number of people have reported that MS Support has had to
take remote control of their computers and "do stuff" to make the installation work.
Sorry, that is not an adequate answer, but it is all I know at this time.