While placing rail B, it connects to rail A, even though rail A already has rails connected at both ends. This appears to only affect rails placed on an incline.

Replacing rail A with a powered rail prevents the connection, but changing rail A back to a standard rail after rail B has been placed still causes A and B to connect.

This is in version 1.14.1, but the site wouldn't let me type that in, and only gave 1.14.09 as an option.