When powered rails are on a slope (like a hill) they are fine, but once they are powered they look inverted and the rail slope is flipped around away from the block, rail carts can still go over it easily so it looks to be a graphical glitch. It only does this when rails are facing east/west

Video in the attachments (When it stopped is when minecraft crashed)

Crash
java.lang.IllegalArgumentException: Cannot get property azi

as it does not exist!
at ayx.b(SourceFile:120)
at aqq.a(SourceFile:282)
at bnw.c(SourceFile:154)
at bnw.b(SourceFile:71)
at bnw.a(SourceFile:48)
at bnm.a(SourceFile:203)
at cdn.b(SourceFile:993)
at bmi.ap(SourceFile:886)
at bmi.a(SourceFile:303)
at net.minecraft.client.main.Main.main(SourceFile:120)