Strange generating lava in caves

Works as intended. Lava is meant to generate in caves...

I know, I mean that streams of lava are too long (look at the screen-shots), when you pour lava from the bucket, streams are many shorter.

It's normal it's the way lava/water finding holes if theres hole, respectively fallout within 4 blocks the lava will find its way to it and if theres multiple holes in different high (Y) it will look strange but this is minecraft.

This is not too long since the lava is flowing down the "stairs".
If you pour lava on flat floor, it won't spread more than 5 blocks.