By Gareth James
Wales’ Olympic bronze medalist was eighth after her first run in Winterberg, clocking 57.92secs.
But a tough second run of 58.25 secs saw the 32-year-old from Wrexham slip to 12th with a combined time of 1:56.17.
Deas still led the trio of British entrants with Ashleigh Pittaway 15th and Madelaine Smith finishing 18th.
It was Deas’ first World Cup outing since the rounds at Sigulda in Latvia where she finished fifth and sixth.
Those were her best performances on the World Cup circuit for 18 months.
The World Cup round also incorporated the European Championships with Deas moving up one place to 11th with Canada’s Elisabeth Maier not counting.
Russia’s Elena Nikitina finished first overall as she defended her European title with a combined time of 1:55.10.
Germany’s Tina Hermann was second (1:55.18) with Austria’s Janine Flock third in 1:55.29.
In the men’s skeleton, Craig Thompson claimed a career best fifth for GB having been sixth and seventh in Sigulda.
Like Deas, the 28-year-old had sat out the two rounds in Igls.
The World Cup circuit now moves on to St Moritz in Switzerland before returning to Germany for Race 7 in Konigssee.
The competition concludes back in Igls, Austria, with the World Championships following in Altenberg, Germany in early February.