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Sometimes I open the saved tvpp, blending mode of all layers is changing to the just 'color' for a few years.
but didn't no why.

I found the reason and tested several times.
'View current layer' while saving destroys all of the layer blending mode of saved file.

You are good!
a great bug catcher, you should be invited to be a betatester.

Nice!
Hard to reproduce this one and never put the finger on it!

Thank you for your feedback.
The dev team was able to fix this bug for the next update.