The caravan is stuck) – a universal phrase for any stop.
ahaha
that's also a great option )) and most importantly – it's short. The text will definitely fit.
UPD: yes, I think your option is the best one for me. Because it also has a notification at the top that "some caravans cannot move further." And why can't they move further? That's right! Because they are "stuck"! :D It seems quite logical and sounds normal. I'll go and rewrite the text in my version.