Cutting back toward the rail you're shooting from is a back cut - and there are also back cuts to the side pockets. They're also "blind pocket" shots, but without shooting away from a rail.
I think both of the shots shown below are back cuts.
pj
chgo
View attachment 1059
I think there is a simple definition of what is, or is not a back cut.
Somewhat like Sigel's explanation of when to draw and when to follow on a straight pool break shot:
Draw a line thru the center of the OB parallel to the rail.
Do the same for the CB.
If the CB line is closer to the rail, it is a back cut.
A related concept is 'blind' cuts. These are shots where the pocket is not visible
in the line-of-sight of the shot.
I would expect players like the OP who struggle with back cuts would also be
challenged by blind cuts.
Before you ask - not all back cuts are blind, not all blind cuts are back.
IMHO - a quick identifier for intermediate players is they consistently miss blind
cuts that are easier than non-blind cuts which they consistently make.
Dale