Importing stills - images are darker

Hi
I’ve taken a few stills for an animation, where I have some some fancy jumping moves with my characters, but I use rigs in the shot.
I export each shot one by one and photoshop the rigs out. I don’t change the brightness or contact, just erase the rigs. They are saved as PNG, the same filetype as the iStopmotion images exported.
However, when I import the images back into the timeline, they come in a few shades darker than my other frames. This means in the final animation, I have a gentle strobing light effect.
Does anyone have any ideas on how I could resolve this?

Thanks!

Thanks for any help or ideas! :slight_smile: