PotPlayer: Frame step gone crazy

[panorek]

For some 2-3 weeks long, probably but not for sure after PotPlayer update,
the frame stepping mechanism has gone haywire.

Previously, the transition between frames occurred at fixed 42 ms intervals.
[using D and F shortcuts]

Now, the intervals between steps vary randomly, ranging from a few milliseconds up to approximately 200 ms.
At the same time, the frame number does not update with every step—while the timestamp and the image change, the frame number remains the same. It only updates upon a subsequent step, at which point the frame number catches up. This can happen for up to 3 or 4 steps without the frame number being updated.

Even more bizarrely, sometimes, rather rarely, moving step forward in the sequence causes the timestamp to decrease, or moving step backward causes it to increase.

Does anyone have any idea what might have gone wrong?
How to bring it back to stable interval?