The bug
It seem that when you push rails they have z-fighting. I don't know what is the reason for it maybe that the game first renders the rail at the new position and then removes it at the old one.
Attachments
Comments


confirmed for 16w20a

Confirmed for 17w17b
Can confirm for MC 1.12.1.

Confirmed for 1.13.1.

Can confirm for 19w34a

Unable to reproduce in 1.16.2 Pre-Release 1

Cannot reproduce either in 1.16.2 Pre-Release 1