RO2 Tanks move slower? (after the update)

After having a long session today, I noticed first on Demnyask(Ya I probably spelled it wrong) the german tank (pIII) did not seem to want to go above 10km/h but after driving it a little bit it went faster but anytime I stopped it would go slow again.





Same thing happened on Barashka, but this time I was in the Russian tank (t70). Is this intentional or a bug or what?