Yes, I'm also seeing forts disappearing rapidly in bad weather, even though that's how things should be according to the new patch(es).
The patch notes are, however, confusing.
According to the 1.05.02 patch notes, new fort decay rates were put in place. According to the 1.05.05 patch notes, those decay rates were then doubled. In both cases, the new decay rates are also shown. However, the 1.05.11 patch notes again mention that the decay rate has been doubled, but without the new rates being displayed. That would suggest that decay rates have been quadrupled, which may or may not actually be as intended. It could also be that Gary or Pavel had forgotten that the rates had already been doubled once after the new decay rates were added.
WitE Alpha tester
Panzer Corps Beta tester
Unity of Command scenario designer