Clakka, I think the ‘experts ‘would say there is no normal or unusual. But they don’t really know what to say when it becomes a difference in desire.
I would say it’s not at all unusual, many things change our desires health, boredom, tiredness, or purely just simply gone off ‘it’ as in going off foods you used to love.
The problem is what to do about it when there is an imbalance, talking openly, setting aside special time with a cosy meal & drink or the age old grin & bear it! Not much help I know ,but you are not alone,I think staying a bit cuddly & affectionate can help & even if there aren’t any fireworks,you may find an occasionall glowing ember?