What definition of strong are you using? Ruble (only one l) has historically been around 85:1 and now its ~60:1. (Rubles:Euros, i.e. 85 Rubles for 1 Euro)
Can you actually trade ruble? For some reason, for example, Sep-2022 futures chart for ruble has a gap between Jun 15 and today. And forex.com claims USD/RUB and EUR/RUB are unavailable for trading.