Worked algae doesn't receive bonus

[SpookyDillows]

I'm on Rising Tide and sent a work barge to build an improvement on the algae (basic yield: 2 food, 1 production) outside my capital.

The work barge is supposed to endow it with +1 energy but after the work was done there was no energy bonus on the tile. I've tried removing and adding a population to work the tile (in case it's just a display error) but there really is no energy yield there.

BTW: Really enjoying Rising Tide so far, after spending 330 hours on BE. Loving the new diplomacy system, despite the minor quibbles reported by other elsewhere.

CORRECTION: The algae outside my land-based capital actually has the +1 energy. It's the algae next to my sea-based city that has not acquired the +1 energy after building the improvement. I assume this is still a bug as the tooltip on the tile states that it gains +1 energy when improved?

 

[SpookyDillows]

Update: After reloading the game twice I've observed that the missing energy yield on the algae tile has appeared (but only the second time, not the first!)

So this is an intermittent problem - curiouser and curiouser....