Wrong starting format measures ADOBE ILLUSTRATOR IN CREATIVE CLOUD
WRONG STARTING SIZES B FORMAT IN ADOBE ILLUSTRATOR
B4 size is 250x353mm
B5 size is 176x250mm
I was keep getting wrong printed formats because i was just pressing given model without carefully lookout.
D G commented
182 x 257 is the japanese "JIS B5", according to google. Same with the other, its the japanese sizing.
JIS = Japanese industrial Standards (...organisation)
So its a wrong/incomplete title, or maybe it has sth to do with your language / region settings?