The Orthodox priests that I know generally slip their cassock on when they arrive at the church and wear ordinary street clothes underneath.
FSSP priests, on the other hand, wear their cassocks everywhere.
My pastor, and Eastern Catholic priest, wears western clerical clothes if he’s working outside the parish, street clothes if he’s not working, and a riassa/cassock at the parish.
Unusual, but not unheard of.
This is Fr. Thomas Hopko, a well-known Orthodox priest.
https://i.ytimg.com/vi/FlJvDz3ZtTw/hqdefault.jpg
And here you have Archbishop Paul, Metropolitan of the Antiochian Orthodox Church in Australia.
https://oca.org/cdn/images/news/2016-0726-svotsaustralia2.jpg