So I found a bug a few months ago on bedrock when I was trying to create an automated Minecart system and found out that you can slope rails onto nothing with pushing.
Linked issues
is duplicated by 5
MCPE-163486
Rails are permanently sloped when adjacent rail is pulled by sticky piston
Resolved
MCPE-145543
This is the bug about Rails when i activate the piston
Resolved
MCPE-122851
Rail direction bug
Resolved
MCPE-143172
You can get a rail on top of a rail.
Resolved
MCPE-151242
The rail is just bugged
Resolved
I found this problem on PC and iphone, v1.21.101