Railgun not building after sabotage repair

Hi - playing finland in game 438469.
I started building a railgun in Tornea. Sabotage damaged some of the installations - the railways, I think, possibly also the factory, and the railgun completion time was put back to >24 days.
I repaired the facilities, but the completion time didn't change for two days.
Now it has changed but it's due to be finished in 23 days 22hours. All the buildings are repaired and working fine.
This must be a bug, no?

Thanks!