Sovereignty claim rescinded

Background:  I use my old capital as lab for the new towns.  One of these experiments resulted in a sov level 3 square with a level 2 cattle ranch.  Actually I even had a cattle ranch 5 on sov level 5 for some time, yielding a 5*5=25% cow bonus.  But it became soon clear that I can't really afford to pay 2400 clay + 2400 iron + 2400 stone + 2400 wood per hour for faster cows in a still growing town.

 Therefore I used the square for a mineshaft 5 (iron bonus) with no upkeep costs per hour, and built three cattle ranches at level 2 for a 3*2*5=30% cow bonus with upkeep costs of 3*300=900 instead of 2400 each per hour.

With a cattle ranch 2 on a sov level 3 forest square my troops refused to justify the third level for military reasons, and my merchants decided to get rid of it.  That resulted in the following system message:

All sov costs and the complete cow bonus immediately vanished.  The status of the square changed from "balanced" to "falling".  I tried to stop the fall below level 2 by an immediate occupation minutes later, but that only allowed to get back to a balanced level 3.  And of course I was offline when the procedure finally reached level 2, and continued to fall.  Some hours later my sovyet army occupied the square again for a few minutes, and I claimed sovereignty again.  

The status immediately went from "falling" to "rising", all costs for level 2 and the cow bonus were re-activated, and the existing cattle ranch 2 survived the few hours in free fall towards level 1.