Popper doesn't flip

[NemoDima]

CodePen demo

https://codepen.io/vovaltus/pen/rNNjONg

Steps to reproduce the problem

1. Move "Drag me" popper left
2. "Flipping popper" doesn't flip

What is the expected behavior?

"Flipping popper" flip

What went wrong?

"Flipping popper" doesn't flip
Please, check zipped .flv file
2019-10-21 17-39-30.zip

Any other comments?

It works properly if I use:
flip: { behavior: ['left', 'right'] },
instead of
flip: { behavior: ['left-start', 'right-start'] },

https://codepen.io/vovaltus/pen/oNNYRKb?editors=0010
Please, check zipped .flv file
2019-10-21 17-40-30.zip

Maybe it corresponds to #512 and #754 but without documentation or explanation, I can't understand how I can solve it.

Appreciated for help.

[NemoDima]

@FezVrasta please look at this issue.
I'll be very appreciated.
Regards, Dmytro

[FezVrasta]

It looks like it works even if you define ['left', 'right-start']. It could be a valid workaround for you.

I'm not sure why this is happening, it looks like a bug.

I cleaned up the CodePen for future reference (ignore it):
https://codepen.io/FezVrasta/pen/RwwLBwY

[NemoDima]

Thank you a lot!