Does anyone have an explanation for this?

I have a copy of Hidden, The: Special Edition (1987) [LVD9526]. If I play the special features disc in my CLD-R7G, it will auto pause at the first still frame (frame 66) as it's supposed to, but then if I try to skip ahead one frame most of the time it will show the next frame for a second or two and then skip back. You can see the frame counter on the front panel move ahead and then back. If I jump to the next chapter there I can move back and forward between frames normally.

I thought maybe the player is broken or out of adjustment, so I tried another CLD-R7G and it did the same thing.

I then tried the disc in a DVL-909. I could move between frames in the first chapter normally. But when I hit eject, the player got confused trying to slow down the disc, gave up, and just let the disc free spin, eventually opening the tray after the disc finally came to a stop on its own. The main movie disc also has the same spin down problem but otherwise plays fine. I tried a bunch of other discs and the DVL-909 can spin those down normally. It's only the ones from The Hidden set that it has trouble with.

There is no noticeable damage or rot on either of the discs. Other than what is mentioned above they play fine with good video quality in the CLD-R7Gs and the DVL-909.

I had this issue years ago on some CAV disc, not this same disc.
I think its just a manufacturing flaw that happened. I remember reading that on early discovision discs, maybe Frenzy? there was an issue similar to this.

Seems like its an odd ball flaw and you either live with it or get another disc.
You can also keep pressing play to see what changes?? Also try flipping the disc and see if the issue still happens.

Players don’t have issues spinning down discs unless there is a grip issue.

If the reverse torque moment doesn’t successfully stop the disc (because it slipped) it will have to slow down from whatever speed it’s at (top speed if this is a CAV disc) to zero just from friction which can take a long time. When the spindle eventually sees 0 RPM it will open the door. Likely the players don’t achieve enough traction with this disc for the stopping moment.

As for why there are issues with frame by frame…I’m not sure. It could be related or maybe it’s not. If I cared I’d take some blue masking tape and cover the labels to see if the different traction surfaces affect the frame by frame.