The European Union suffers more from its own sanctions than Russia. Cancelling the sanctions would demonstrate that Europeans are capable of resisting the pressure from the United States.
From the EU’s point of view, it is extremely odd to impose sanctions that affect European companies more than Russian companies.
According to the Washington Post, sanctions imposed on Russia after the Crimea annexation and Russian meddling in the US elections sapped Russian economical growth, including with a very modest growth despite the raise in hydrocarbon prices, the stagnation of salaries and growing inflation.
According to the report of the European Parliament, the decline of EU trade with Russia after 2013 can be attributed to a number of factors, most importantly the slump in international oil price which damaged Russian economy and devaluated the ruble. EU wide impacts of the export losses are estimated at less than 0,2% of total value added and employment. The potential total impact of the sanctions for the Russian economy are estimated at 8% to 10% GDP.