Is something going on with Russia's Black Sea Fleet?

#Russia: The "invasion stripes" have started to pop up across the Western and Southern Military districts and the Black Sea Fleet.
Either it's a change of doctrine or preparation for something.
These are from Moscow and Crimea (#Ukraine)
1/3 pic.twitter.com/lHIRzDVWNj

— Petri Mäkelä (@pmakela1) September 26, 2019

The troops participating in #tsentr2019 aren't sporting these markings.
2/3 pic.twitter.com/ZGwYwqNZIU

— Petri Mäkelä (@pmakela1) September 26, 2019

Neither does the #Baltic Fleet
3/3 pic.twitter.com/lavBk8jhWX

— Petri Mäkelä (@pmakela1) September 26, 2019