Photoshop render video as image sequence dropping frames

Hi there,

I've been having an issue when trying to export an animation using:
Export > Render Video > Photoshop Image Sequence

The issue: Animation is 12 frames long, when exporting the image sequence frames 5 and 10 are not being exported. So instead of 12 images I only have 10. Has happened multiple times. Have already tried to 'Save As' new file.

Details:

Photoshop CC has recently been updated to 19.1.5

OS: Windows 10

Format: Happens for both PNG and JPEG sequences

Frame rate: Happens both on 12 and 24

Range: All frames

Its always the same 2 frames

The animation is visible fine in the PSD file, the groups/layers match the other frames. There's nothing I can see that would be causing this. If anyone has any ideas I'd be super grateful for any help.