I can only speak for the Habsburg Monarchy:

It's worth noting that the design technically speaking wasn't categorically rejected by the Imperial and Royal Army - the Automobile Department of the Technical-Administrative Military Committee headed by the artillerist Robert Wolf to be more precise - per se, it said that it would be interested in it however it was unwilling to provide the funds needed to build a prototype.

So Burstyn would have to fund the project out of his own pocket but his personal financial situation would not allow him to do so nor had he any contacts in the commercial sector that would be willing to cover the expenses.

There are two main reasons why the army was sceptical towards the project:

First, the fact that Burstyn did not have a working prototype and his drafts were still rather vague hurt him quite a lot - to Wolf's eyes, who had no engineering training by the way, the draft looked like just another armoured car similar to Burstyn's earlier designs, he considered it useless for transporting artillery and decided that the army's funds should not be used to create a working prototype.

Secondly, the army budget was anemic to say the least. It had to be agreed to by both Cisleithania and Transleithania, the two halves of the Dual Monarchy which meant that it was always a subject to a relatively hard bargaining, for example the army had between 1889 and 1912 the same manpower ceiling despite an increase in population because the two halves of the Monarchy could not agree on an increase of the military budget. In 1912 a compromise was reached but the money was being allocated mostly on the Navy, artillery and fortifications leaving little for these kinds of projects.

These two issues combined meant that the army was very reluctant to spent their precious funds on these risky projects that existed only on paper, particulary if they seemed like versions of previous designs that the army was not particulary excited about either.

Sources:

DREDGER, John A. Tactics and Procurement in the Habsburg Military, 1866 - 1918, 2017

ROTHENBERG, Gunther E. The Army of Francis Joseph, 1998