same on my surface, w10,browser firefox no scripts active; when trying to return from attacking bandits to city view no response on screen, after reload city screen opens. workable but not nice :)
i may be wrong, but did you also change the option of a quick/free completion of a build once the time left reached 5 minutes?
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probably only during the first build, later builds did offer the free completion on reaching the 5 minutes timer. assume it was/is a glitch ;-)
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looks like...